Sulfonyldiazomethanes, photoacid generations, resist compositions, and patterning process

ABSTRACT

A chemical amplification type resist composition contains as a photoacid generator a sulfonyldiazomethane compound of formula (1) wherein R is H or C 1-4  alkyl or alkoxy, G is SO 2  or CO, R 3  is C 1-10  alkyl or C 6-14  aryl, p is 1 or 2, q is 0 or 1, p+q=2, n is 0 or 1, m is 3 to 11, and k is 0 to 4. The composition is suited for microfabrication, especially by deep UV lithography because of many advantages including improved resolution and improved pattern profile after development.

This invention relates to novel sulfonyldiazomethane compounds,photoacid generators for resist compositions, resist compositionscomprising the photoacid generators, and a patterning process using thesame. The resist compositions, especially chemical amplification typeresist compositions are sensitive to such radiation as UV, deep UV,electron beams, x-rays, excimer laser beams, γ-rays, and synchrotronradiation and suitable for the microfabrication of integrated circuits.

BACKGROUND OF THE INVENTION

While a number of efforts are currently being made to achieve a finerpattern rule in the drive for higher integration and operating speeds inLSI devices, deep-ultraviolet lithography is thought to hold particularpromise as the next generation in microfabrication technology.

One technology that has attracted a good deal of attention recentlyutilizes as the deep UV light source a high-intensity KrF excimer laser,especially an ArF excimer laser featuring a shorter wavelength. There isa desire to have a microfabrication technique of finer definition bycombining exposure light of shorter wavelength with a resist materialhaving a higher resolution.

In this regard, the recently developed, acid-catalyzed, chemicalamplification type resist materials are expected to comply with the deepUV lithography because of their many advantages including highsensitivity, resolution and dry etching resistance. The chemicalamplification type resist materials include positive working materialsthat leave the unexposed areas with the exposed areas removed andnegative working materials that leave the exposed areas with theunexposed areas removed.

In chemical amplification type, positive working, resist compositions tobe developed with alkaline developers, an alkali-soluble phenol or aresin and/or compound in which carboxylic acid is partially or entirelyprotected with acid-labile protective groups (acid labile groups) iscatalytically decomposed by an acid which is generated upon exposure, tothereby generate the phenol or carboxylic acid in the exposed area whichis removed by an alkaline developer. Also, in similar negative workingresist compositions, an alkali-soluble phenol or a resin and/or compoundhaving carboxylic acid and a compound (crosslinking agent) capable ofbonding or crosslinking the resin or compound under the action of anacid are crosslinked with an acid which is generated upon exposurewhereby the exposed area is converted to be insoluble in an alkalinedeveloper and the unexposed area is removed by the alkaline developer.

On use of the chemical amplification type, positive working, resistcompositions, a resist film is formed by dissolving a resin having acidlabile groups as a binder and a compound capable of generating an acidupon exposure to radiation (to be referred to as photoacid generator) ina solvent, applying the resist solution onto a substrate by a variety ofmethods, and evaporating off the solvent optionally by heating. Theresist film is then exposed to radiation, for example, deep UV through amask of a predetermined pattern. This is optionally followed bypost-exposure baking (PEB) for promoting acid-catalyzed reaction. Theexposed resist film is developed with an aqueous alkaline developer forremoving the exposed area of the resist film, obtaining a positivepattern profile. The substrate is then etched by any desired technique.Finally the remaining resist film is removed by dissolution in a removersolution or ashing, leaving the substrate having the desired patternprofile.

The chemical amplification type, positive working, resist compositionsadapted for KrF excimer lasers generally use a phenolic resin, forexample, polyhydroxystyrene in which some or all of the hydrogen atomsof phenolic hydroxyl groups are protected with acid labile protectivegroups. Iodonium salts, sulfonium salts, and bissulfonyldiazomethanecompounds are typically used as the photoacid generator. If necessary,there are added additives, for example, a dissolution inhibiting orpromoting compound in the form of a carboxylic acid and/or phenolderivative having a molecular weight of up to 3,000 in which some or allof the hydrogen atoms of carboxylic acid and/or phenolic hydroxyl groupsare protected with acid labile groups, a carboxylic acid compound forimproving dissolution characteristics, a basic compound for improvingcontrast, and a surfactant for improving coating characteristics.

Bissulfonyldiazomethanes as shown below are advantageously used as thephotoacid generator in chemical amplification type resist compositions,especially chemical amplification type, positive working, resistcompositions adapted for KrF excimer lasers because they provide a highsensitivity and resolution and eliminate poor compatibility with resinsand poor solubility in resist solvents as found with the sulfonium andiodonium salt photoacid generators.

Although these photoacid generators are highly lipophilic and highlysoluble in resist solvents, they have poor affinity to or solubility indevelopers so that upon development and/or resist removal, the photoacidgenerators can be left on the substrate as insoluble matter (consistingof the photoacid generator or a mixture thereof with the resin).

For example, upon development, the resist material which has pooraffinity to or solubility in a developer deposits on developed spaces inthe exposed area or on lines in the unexposed area as foreign matter.

JP-A 3-103854 discloses bis(4-methoxyphenylsulfonyl)diazomethane as aphotoacid generator having a methoxy group introduced therein. As longas we confirmed, the methoxy group is not fully effective. The photoacidgenerator is often left on the substrate as insoluble matter (consistingof the photoacid generator or a mixture thereof with the resin) upondevelopment and/or resist film removal.

If unsubstituted bis(phenylsulfonyl)diazomethane orbis(cyclohexylsulfonyl)diazomethane having alkyl groups instead of arylgroups is used in a resist material as the photoacid generator forreducing lipophilic property, resolution is deteriorated. If it is addedin large amounts, the problem of insoluble matter upon developmentand/or resist film removal remains unsolved.

Aside from the countermeasure for foreign matter, JP-A 10-90884discloses to introduce such an acid labile group as t-butoxycarbonyloxy,ethoxyethyl or tetrahydropyranyl into disulfonediazomethane for thepurpose of improving the contrast of positive resist material. Weempirically found that these compounds are unstable and ineffective foreliminating the foreign matter upon development and resist film removal.

Searching for a countermeasure to the foreign matter problem, we alreadysynthesized sulfonyldiazomethanes having an acyl group (e.g., acetyl) ormethanesulfonyl group introduced therein and found that they were usefulas the photoacid generator in chemical amplification type resistcomposition. Since these arylsulfonyldiazomethanes having an acyl groupor methanesulfonyl group introduced therein lack stability under basicconditions during their synthesis, the yield of diazo formation issometimes low. See JP-A 2001-055373 and JP-A 2001-106669.

It is known from JP-A 8-123032 to use two or more photoacid generatorsin a resist material. JP-A 11-72921 discloses the use of aradiation-sensitive acid generator comprising in admixture a compoundwhich generates a sulfonic acid having at least three fluorine atomsupon exposure to radiation and a compound which generates a fluorineatom-free sulfonic acid upon exposure to radiation, thereby improvingresolution without inviting nano-edge roughness and film surfaceroughening. JP-A 11-38604 describes that a resist composition comprisingan asymmetric bissulfonyldiazomethane such as a bissulfonyldiazomethanehaving an alkylsulfonyl or arylsulfonyl group or abissulfonyldiazomethane having an arylsulfonyl or alkoxy-substitutedarylsulfonyl group and a polyhydroxystyrene derivative having acidlabile groups as the polymer has a resolution at least comparable toprior art compositions, a sufficient sensitivity and significantlyimproved heat resistance. However, we empirically found that theseresist compositions are unsatisfactory in resolution and in the effectof eliminating the foreign matter on the pattern upon development. Fromthe synthetic and industrial standpoints, it is difficult to obtainbilaterally asymmetric bissulfonyldiazomethanes.

Aside from the above-discussed problem of insoluble matter upondevelopment and/or removal, there is also a problem that the patternprofile often changes when the period from exposure to post-exposurebaking (PEB) is prolonged, which is known as post-exposure delay (PED).Such changes frequently reveal as a slimming of the line width ofunexposed areas in the case of chemical amplification type positiveresist compositions using acetal and analogous acid labile groups, andas a thickening of the line width of unexposed areas in the case ofchemical amplification type positive resist compositions usingtert-butoxycarbonyl (t-BOC) and analogous acid labile groups. Since theperiod from exposure to PEB is often prolonged for the operationalreason, there is a desire to have a stable resist composition which isfree from such changes, that is, has PED stability.

The solubility of photosensitive agents or photoacid generators was theproblem from the age when quinonediazide photosensitive agents were usedin non-chemical amplification type resist materials. Specificconsiderations include the solubility of photoacid generators in resistsolvents, the compatibility of photoacid generators with resins, thesolubility (or affinity) of photo-decomposed products after exposure andPEB and non-decomposed compound (photoacid generator) in a developer,and the solubility of the photoacid generator and photo-decomposedproducts thereof in a remover solvent upon resist removal or peeling. Ifthese factors are poor, there can occur problems including precipitationof the photoacid generator during storage, difficulty of filtration,uneven coating, striation, abnormal resist sensitivity, and foreignmatter, left-over and staining on the pattern and in spaces afterdevelopment.

The photoacid generator in resist material is required to meet a fullyhigh solubility in (or compatibility with) a resist solvent and a resin,good storage stability, non-toxicity, effective coating, a well-definedpattern profile, PED stability, and no foreign matter left duringpattern formation after development and upon resist removal. Theconventional photoacid generators, especially diazodisulfone photoacidgenerators do not meet all of these requirements.

As the pattern of integrated circuits becomes finer in these days, ahigher resolution is, of course, required, and the problem of foreignmatter after development and resist removal becomes more serious.

SUMMARY OF THE INVENTION

An object of the invention is to provide a novel sulfonyldiazomethanefor use in a resist composition, especially of the chemicalamplification type, such that the resist composition minimizes theforeign matter left after coating, development and resist removal andensures a well-defined pattern profile after development. Another objectof the invention is to provide a photoacid generator for resistcompositions, a resist composition comprising the photoacid generator,and a patterning process using the same.

We have found that by using a sulfonyldiazomethane compound of thegeneral formula (1), especially formula (1a), to be defined below, asthe photoacid generator in a resist composition, there are achieved anumber of advantages including dissolution, storage stability, effectivecoating, minimized line width variation or shape degradation duringlong-term PED, minimized foreign matter left after coating, developmentand resist removal, a well-defined pattern profile after development,and a high resolution enough for microfabrication, especially by deep UVlithography. Better results are obtained when a sulfonyldiazomethanecompound of the formula (1), especially formula (1a), is used as thephotoacid generator in a chemical amplification type resist composition,typically chemical amplification positive type resist compositioncomprising a resin which changes its solubility in an alkaline developerunder the action of an acid as a result of scission of C—O—C linkages.The composition exerts its effect to the maximum extent when processedby deep UV lithography.

In a first aspect, the invention provides a sulfonyldiazomethanecompound having the following general formula (1).

Herein R is independently hydrogen or a substituted or unsubstituted,straight, branched or cyclic alkyl or alkoxy group of 1 to 4 carbonatoms, G is SO₂ or CO, R³ is a substituted or unsubstituted, straight,branched or cyclic alkyl group of 1 to 10 carbon atoms or a substitutedor unsubstituted aryl group of 6 to 14 carbon atoms, p is 1 or 2, q is 0or 1, satisfying p+q=2, n is 0 or 1, m is an integer of 3 to 11, and kis an integer of 0 to 4.

Typical sulfonyldiazomethane compounds have the following generalformula (1a).

Herein R, n, m and k are as defined above.

In a second aspect, the invention provides a photoacid generator for achemical amplification type resist composition comprising thesulfonyldiazomethane compound of formula (1) or (1a).

In a third aspect, the invention provides a chemical amplification typeresist composition comprising (A) a resin which changes its solubilityin an alkaline developer under the action of an acid, (B) thesulfonyldiazomethane compound of formula (1) or (1a) which generates anacid upon exposure to radiation, and optionally, (C) a compound capableof generating an acid upon exposure to radiation, other than component(B). The resist composition may further contain (D) a basic compound,(E) an organic acid derivative, and an organic solvent.

The resin (A) typically has such substituent groups having C—O—Clinkages that the solubility in an-alkaline developer changes as aresult of scission of the C—O—C linkages under the action of an acid.

In a preferred embodiment, the resin (A) is a polymer containingphenolic hydroxyl groups in which hydrogen atoms of the phenolichydroxyl groups are substituted with acid labile groups of one or moretypes in a proportion of more than 0 mol % to 80 mol % on the average ofthe entire hydrogen atoms of the phenolic hydroxyl groups, the polymerhaving a weight average molecular weight of 3,000 to 100,000.

More preferably, the resin (A) is a polymer comprising recurring unitsof the following general formula (2a):

wherein R⁴ is hydrogen or methyl, R⁵ is a straight, branched or cyclicalkyl group of 1 to 8 carbon atoms, x is 0 or a positive integer, y is apositive integer, satisfying x+y≦5, R⁶ is an acid labile group, S and Tare positive integers, satisfying 0<T/(S+T)≦0.8,

wherein the polymer contains units in which hydrogen atoms of phenolichydroxyl groups are partially substituted with acid labile groups of oneor more types, a proportion of the acid labile group-bearing units is onthe average from more than 0 mol % to 80 mol % based on the entirepolymer, and the polymer has a weight average molecular weight of 3,000to 100,000.

In another preferred embodiment, the resin (A) is a polymer comprisingrecurring units of the following general formula (2a′):

wherein R⁴ is hydrogen or methyl, R⁵ is a straight, branched or cyclicalkyl group of 1 to 8 carbon atoms, R⁶ is an acid labile group, R^(6a)is hydrogen or an acid labile group, at least some of R^(6a) being acidlabile groups, x is 0 or a positive integer, y is a positive integer,satisfying x+y≦5, M and N are positive integers, L is 0 or a positiveinteger, satisfying 0<N/(M+N+L)≦0.5 and 0<(N+L)/(M+N+L)≦0.8,

wherein the polymer contains on the average from more than 0 mol % to 50mol % of those units based on acrylate and methacrylate, and alsocontains on the average from more than 0 mol % to 80 mol % of acidlabile group-bearing units, based on the entire polymer, and the polymerhas a weight average molecular weight of 3,000 to 100,000.

In a further preferred embodiment, the resin (A) is a polymer comprisingrecurring units of the following general formula (2a″):

wherein R⁴ is hydrogen or methyl, R⁵ is a straight, branched or cyclicalkyl group of 1 to 8 carbon atoms, R⁶ is an acid labile group, R^(6a)is hydrogen or an acid labile group, at least some of R^(6a) being acidlabile groups, x is 0 or a positive integer, y is a positive integer,satisfying x+y≦5, yy is 0 or a positive integer, satisfying x+yy≦5, Aand B are positive integers, C, D and E each are 0 or a positiveinteger, satisfying 0<(B+E)/(A+B+C+D+E)≦0.5 and0<(C+D+E)/(A+B+C+D+E)≦0.8,

wherein the polymer contains on the average from more than 0 mol % to 50mol % of those units based on indene and/or substituted indene, and alsocontains on the average from more than 0 mol % to 80 mol % of acidlabile group-bearing units, based on the entire polymer, and the polymerhas a weight average molecular weight of 3,000 to 100,000.

In these preferred embodiments, the acid labile group is preferablyselected from among groups of the following general formulae (4) to (7),tertiary alkyl groups of 4 to 20 carbon atoms, trialkylsilyl groupswhose alkyl moieties each have 1 to 6 carbon atoms, oxoalkyl groups of 4to 20 carbon atoms, and aryl-substituted alkyl groups of 7 to 20 carbonatoms,

wherein R¹⁰ and R¹¹ each are hydrogen or a straight, branched or cyclicalkyl having 1 to 18 carbon atoms, and R¹² is a monovalent hydrocarbongroup of 1 to 18 carbon atoms which may contain a heteroatom, a pair ofR¹⁰ and R¹¹, R¹⁰ and R¹², or R¹¹ and R¹² may together form a ring, withthe proviso that R¹⁰, R¹¹, and R¹² each are a straight or branchedalkylene of 1 to 18 carbon atoms when they form a ring,

R¹³ is a tertiary alkyl group of 4 to 20 carbon atoms, a trialkysilylgroup in which each of the alkyls has 1 to 6 carbon atoms, an oxoalkylgroup of 4 to 20 carbon atoms, or a group of the formula (4), z is aninteger of 0 to 6,

R¹⁴ is a straight, branched or cyclic alkyl group of 1 to 8 carbon atomsor an aryl group of 6 to 20 carbon atoms which may be substituted, h is0 or 1, i is 0, 1, 2 or 3, satisfying 2h+i=2 or 3,

R¹⁵ is a straight, branched or cyclic alkyl group of 1 to 8 carbon atomsor an aryl group of 6 to 20 carbon atoms which may be substituted, R¹⁶to R²⁵ are each independently hydrogen or a monovalent hydrocarbon groupof 1 to 15 carbon atoms which may contain a heteroatom, R¹⁶ to R²⁵,taken together, may form a ring, each of R¹⁶ to R²⁵ is a divalenthydrocarbon group of 1 to 15 carbon atoms which may contain a heteroatomwhen they form a ring, or two of R¹⁶ to R²⁵ which are attached toadjoining carbon atoms may bond together directly to form a double bond.

Preferably, the organic solvent contains a propylene glycol alkyl etheracetate, an alkyl lactate or a mixture thereof.

Also contemplated herein is a process for forming a pattern, comprisingthe steps of applying the resist composition onto a substrate to form acoating; heat treating the coating and exposing the coating to highenergy radiation with a wavelength of up to 300 nm or electron beamthrough a photomask; optionally heat treating the exposed coating, anddeveloping the coating with a developer.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Sulfonyldiazomethane

In the first aspect of the invention, novel sulfonyldiazomethanecompounds having a long-chain alkyl group or alkoxyl group are provided.They are represented by the general formula (1).

Herein R is independently hydrogen or a substituted or unsubstituted,straight, branched or cyclic alkyl or alkoxy group of 1 to 4 carbonatoms, G is SO₂ or CO, and R³ is a substituted or unsubstituted,straight, branched or cyclic alkyl group of 1 to 10 carbon atoms or asubstituted or unsubstituted aryl group of 6 to 14 carbon atoms. Thesubscript p is 1 or 2, q is 0 or 1, satisfying p+q=2, n is 0 or 1, m isan integer of 3 to 11, and k is an integer of 0 to 4.

Preferred among the sulfonyldiazomethane compounds of formula (1) aresulfonyldiazomethane compounds having long-chain alkyl or alkoxyl groupsof the following general formula (1a).

Herein R is independently hydrogen or a substituted or unsubstituted,straight, branched or cyclic alkyl or alkoxy group of 1 to 4 carbonatoms, n is 0 or 1, m is an integer of 3 to 11, and k is an integer of 0to 4.

In formula (1) or (1a), R may be the same or different and stands forhydrogen or substituted or unsubstituted, straight, branched or cyclicalkyl or alkoxy groups of 1 to 4 carbon atoms, for example, hydrogen,methyl, ethyl, n-propyl, sec-propyl, cyclopropyl, n-butyl, sec-butyl,iso-butyl, tert-butyl, methoxy, ethoxy, n-propyloxy, sec-propyloxy,n-butyloxy, sec-butyloxy, iso-butyloxy, and tert-butyloxy. Of these,hydrogen, methyl, ethyl, n-propyl and isopropyl are preferred, withhydrogen and methyl being most preferred.

The subscript k is an integer of 0 to 4, and k is preferably 0, 1 or 2when R is C₁₋₄ alkyl or alkoxy. The substitution position of R isarbitrary and preferably 2-position (ortho position) relative to thesulfonyl group. It is more preferred that methyl be located at the2-position (ortho position) relative to the sulfonyl group. When k is 2to 4, substituent groups (R) which may be either identical or differentmay be further located at positions other than 2-position.

In formula (1) or (1a), R³ stands for substituted or unsubstituted,straight, branched or cyclic alkyl groups of 1 to 10 carbon atoms orsubstituted or unsubstituted aryl groups of 6 to 14 carbon atoms.Illustrative, non-limiting, examples of the straight, branched or cyclicalkyl groups include methyl, ethyl, n-propyl, sec-propyl, n-butyl,sec-butyl, iso-butyl, tert-butyl, n-pentyl, sec-pentyl, cyclopentyl,n-hexyl, and cyclohexyl. Illustrative, non-limiting, examples of thesubstituted or unsubstituted aryl groups include phenyl, 4-methylphenyl,4-ethylphenyl, 4-methoxyphenyl, 4-tert-butylphenyl, 4-tert-butoxyphenyl,4-cyclohexylphenyl, 4-cyclohexyloxyphenyl, 2,4-dimethylphenyl,2,4,6-trimethylphenyl, 2,4,6-triisopropylphenyl, 1-naphthyl and2-naphthyl. Of these, tert-butyl, cyclohexyl, 4-methylphenyl,2,4-dimethylphenyl and 4-tert-butylphenyl are preferred. G stands forSO₂ or CO. SO₂ is preferred.

The subscript p is equal to 1 or 2, q is equal to 0 or 1, satisfyingp+q=2.

The subscript n is equal to 0 or 1. Preference is given to n=1 for easeof availability of starting reactants and ease of synthesis. In the caseof n=0, a maximum absorption peak near 255 nm attributable toalkoxyphenyl group can be shifted so that the transmittance at 248 nm isincreased as compared with the case where n=1. In this sense, n isselected equal to 0 or 1 depending on the desired transmittance ofresist. The subscript m is an integer of 3 to 11, preferably 5 to 9.Where m is less than 3, the problem of foreign matter left upondevelopment and resist film peeling is not overcome. A value of m inexcess of 11 raises problems of synthesis including too high a boilingpoint of starting thiol reactant.

The sulfonyldiazomethane compounds can be synthesized by the followingmethod although the synthesis method is not limited thereto.

Reference is first made to a sulfonyldiazomethane compound of formula(1) wherein p=2, that is, a symmetric bissulfonyldiazomethane compound.It is desirably synthesized by condensing a substituted thiophenol withdichloromethane under basic conditions as disclosed in JP-A 3-103854.More specifically, an alkyl or alkoxyl-containing thiophenol such as4-(n-hexyloxy)thiophenol is condensed with dichloromethane in an alcoholsolvent such as methanol or ethanol in the presence of a base such assodium hydroxide or potassium hydroxide, obtaining a formaldehydebis(alkylphenylthio)acetal or formaldehyde bis(alkoxyphenylthio)acetal.

Herein, R, n, m and k are as defined above.

Alternatively, a substituted thiophenol is condensed with formaldehyde(para-formaldehyde) under acidic conditions such as sulfuric acid ortrifluoromethanesulfonic acid.

In the case of p=1, that is, an asymmetric sulfonyldiazomethanecompound, reaction is effected between a halomethylthio ether and analkyl or alkoxy-substituted thiophenol. In the case ofsulfonylcarbonyldiazomethane, reaction is conducted between anα-halomethylketone and an alkyl or alkoxy-substituted thiophenol. Thehalomethylthio ether can be prepared from a corresponding thiol,formaldehyde and hydrogen chloride (see J. Am. Chem. Soc., 86, 4383(1964), J. Am. Chem. Soc., 67, 655 (1945), and U.S. Pat. No. 2,354,229).

Herein, R, R³, n, m and k are as defined above, and X is a halogen atom.

In the above procedures, an alkyl or alkoxy-substituted thiophenol isused as the starting reactant. In the case of n=1, that is, having analkoxyl group, a possible method is by using a hydroxythiophenol as thestarting reactant and reacting it with a corresponding alkyl halide asshown below.

Herein, R, R³, n, m and k are as defined above, and X is a halogen atom.

Further, the product is oxidized with an oxidant such as aqueoushydrogen peroxide in the presence of sodium tungstate etc. as describedin JP-A 4-211258, yielding a corresponding sulfonylmethane.

Herein, R, R³, n, m and k are as defined above.

This product is reacted with p-toluenesulfonylazide,p-dodecylbenzenesulfonylazide or p-acetamidobenzenesulfonylazide underbasic conditions into a diazo form, yielding the endsulfonyldiazomethane.

Herein, R, R³, p, q, n, m, k and G are as defined above.

It is noted that the synthesis of alkyl- or alkoxy-substitutedthiophenols is not critical. It can be synthesized by converting analkyl- or alkoxybenzene with chlorosulfuric acid, sulfuric acid/aceticanhydride or the like to a substituted benzene sulfonic acid, thenconverting it with chlorosulfuric acid, thionyl chloride or the like toa substituted benzene sulfonyl chloride, and reducing it with aluminumlithium hydride, hydrochloric acid/zinc or the like as shown below.

Herein R, n, m and k are as defined above.

The halogenated alkylbenzene or halogenated alkoxybenzene is treatedwith metallic magnesium to form a Grignard reagent, which is reactedwith sulfur for acidification. See Romeo B. Wagner and Harry D. Zook,Synthetic Organic Chemistry, John Wiley & Sons, Inc., 1965, 778-781.

Herein R, n, m and K are as defined above, and X is a halogen atom.

The halogenated alkoxybenzene can be synthesized by reacting ahalogenated phenol with CH₃(CH₂)_(m)X under basic conditions. Exemplaryof suitable halogenated phenols are 4-bromophenol,4-bromo-2,6-dimethylphenol, 4-chloro-2-methylphenol,4-chloro-3-methylphenol, 4-chloro-2-isopropyl-5-methylphenol, and3-ethyl-4-chlorophenol. Alternatively, it can be synthesized by reactinga phenol derivative with CH₃(CH₂)_(m)X under basic conditions, followedby reaction with bromine. Exemplary of suitable phenol derivatives arephenol, cresol, xylenol, trimethylphenol, thymol, isothymol,ethylphenol, and 2-tert-butyl-5-methylphenol.

Examples of the sulfonyldiazomethanes of formulae (1) and (1a) areillustrated below, but are not limited thereto. Examples of bilaterallysymmetric bissulfonyldiazomethane includebis(4-n-butylphenylsulfonyl)diazomethane,bis(4-n-pentylphenylsulfonyl)diazomethane,bis(4-n-hexylphenylsulfonyl)diazomethane,bis(4-n-heptylphenylsulfonyl)diazomethane,bis(4-n-octylphenylsulfonyl)diazomethane,bis(4-n-nonylphenylsulfonyl)diazomethane,bis(4-n-decylphenylsulfonyl)diazomethane,bis(4-n-undecylphenylsulfonyl)diazomethane,bis(4-n-dodecylphenylsulfonyl)diazomethane,bis(4-(n-butyloxy)phenylsulfonyl)diazomethane,bis(4-(n-pentyloxy)phenylsulfonyl)diazomethane,bis(4-(n-hexyloxy)phenylsulfonyl)diazomethane,bis(4-(n-heptyloxy)phenylsulfonyl)diazomethane,bis(4-(n-octyloxy)phenylsulfonyl)diazomethane,bis(4-(n-nonyloxy)phenylsulfonyl)diazomethane,bis(4-(n-decyloxy)phenylsulfonyl)diazomethane,bis(4-(n-undecyloxy)phenylsulfonyl)diazomethane,bis(4-(n-dodecyloxy)phenylsulfonyl)diazomethane,bis(3-methyl-4-(n-butyloxy)phenylsulfonyl)diazomethane,bis(3-methyl-4-(n-pentyloxy)phenylsulfonyl)diazomethane,bis(3-methyl-4-(n-hexyloxy)phenylsulfonyl)diazomethane,bis(3-methyl-4-(n-heptyloxy)phenylsulfonyl)diazomethane,bis(3-methyl-4-(n-octyloxy)phenylsulfonyl)diazomethane,bis(3-methyl-4-(n-nonyloxy)phenylsulfonyl)diazomethane,bis(3-methyl-4-(n-decyloxy)phenylsulfonyl)diazomethane,bis(3-methyl-4-(n-undecyloxy)phenylsulfonyl)diazomethane,bis(3-methyl-4-(n-dodecyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-4-(n-butyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-4-(n-pentyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-4-(n-hexyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-4-(n-heptyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-4-(n-octyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-4-(n-nonyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-4-(n-decyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-4-(n-undecyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-4-(n-dodecyloxy)phenylsulfonyl)diazomethane,bis(3,5-dimethyl-4-(n-butyloxy)-phenylsulfonyl)diazomethane,bis(3,5-dimethyl-4-(n-pentyloxy)phenylsulfonyl)diazomethane,bis(3,5-dimethyl-4-(n-hexyloxy)phenylsulfonyl)diazomethane,bis(3,5-dimethyl-4-(n-heptyloxy)phenylsulfonyl)diazomethane,bis(3,5-dimethyl-4-(n-octyloxy)phenylsulfonyl)diazomethane,bis(3,5-dimethyl-4-(n-nonyloxy)phenylsulfonyl)diazomethane,bis(3,5-dimethyl-4-(n-decyloxy)phenylsulfonyl)diazomethane,bis(3,5-dimethyl-4-(n-undecyloxy)phenylsulfonyl)diazomethane,bis(3,5-dimethyl-4-(n-dodecyloxy)phenylsulfonyl)diazomethane,bis(5-isopropyl-2-methyl-4-(n-butyloxy)phenylsulfonyl)diazomethane,bis(5-isopropyl-2-methyl-4-(n-pentyloxy)phenylsulfonyl)diazomethane,bis(5-isopropyl-2-methyl-4-(n-hexyloxy)phenylsulfonyl)diazomethane,bis(5-isopropyl-2-methyl-4-(n-heptyloxy)phenylsulfonyl)diazomethane,bis(5-isopropyl-2-methyl-4-(n-octyloxy)phenylsulfonyl)diazomethane,bis(5-isopropyl-2-methyl-4-(n-nonyloxy)phenylsulfonyl)diazomethane,bis(5-isopropyl-2-methyl-4-(n-decyloxy)phenylsulfonyl)diazomethane,bis(5-isopropyl-2-methyl-4-(n-undecyloxy)phenylsulfonyl)diazomethane,andbis(5-isopropyl-2-methyl-4-(n-dodecyloxy)phenylsulfonyl)diazomethane.

Examples of the bilaterally asymmetric sulfonyldiazomethane include(4-(n-hexyloxy)phenylsulfonyl)(methylsulfonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(tert-butylsulfonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(cyclohexylsulfonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(benzenesulfonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(p-toluenesulfonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(2,4-dimethylphenylsulfonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(4-tert-butylphenylsulfonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(4-tert-butoxyphenylsulfonyl)diazomethane,(4-(n-octyloxy)phenylsulfonyl)(methylsulfonyl)diazomethane,(4-(n-octyloxy)phenylsulfonyl)(tert-butylsulfonyl)diazomethane,(4-(n-octyloxy)phenylsulfonyl)(cyclohexylsulfonyl)diazomethane,(4-(n-octyloxy)phenylsulfonyl)(benzenesulfonyl)diazomethane,(4-(n-octyloxy)phenylsulfonyl)(p-toluene-sulfonyl)diazomethane,(4-(n-octyloxy)phenylsulfonyl)(2,4-dimethylphenylsulfonyl)diazomethane,(4-(n-octyloxy)phenylsulfonyl)(4-tert-butylphenylsulfonyl)diazomethane,and(4-(n-octyloxy)phenylsulfonyl)(4-tert-butoxyphenylsulfonyl)diazomethane.

Examples of the sulfonylcarbonyldiazomethane include(4-(n-hexyloxy)phenylsulfonyl)(methylcarbonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(tert-butylcarbonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(cyclohexylcarbonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(benzoyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(p-toluenecarbonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(2,4-dimethylphenylcarbonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(4-tert-butylphenylcarbonyl)diazomethane,and(4-(n-hexyloxy)phenylsulfonyl)(4-tert-butoxyphenylcarbonyl)diazomethane.

Of these, preferred are bis(4-(n-hexyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-4-(n-hexyloxy)phenylsulfonyl)diazomethane,bis(2,5-dimethyl-4-(n-hexyloxy)phenylsulfonyl)diazomethane,bis(3,5-dimethyl-4-(n-hexyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-5-isopropyl-4-(n-hexyloxy)phenylsulfonyl)diazomethane, andthe like.

Examples of the sulfonyl diazomethane of the general formula (1a)include the compounds having the following formula.

Herein m is as defined above.

The sulfonyldiazomethane compounds of formula (1) or (1a) are useful asthe photoacid generator in resist materials sensitive to radiation suchas ultraviolet, deep ultraviolet, electron beams, x-rays, excimer laserlight, γ-rays, and synchrotron radiation for use in the microfabricationof integrated circuits, especially in chemical amplification type resistmaterials.

Resist Composition

The resist compositions of the invention contain one or more of thesulfonyldiazomethane compounds of formula (1) or (1a). The resistcompositions may be either positive or negative working although theyare preferably of the chemical amplification type. The resistcompositions of the invention include a variety of embodiments,

1) a chemically amplified positive working resist composition comprising(A) a resin which changes its solubility in an alkaline developer underthe action of an acid, (B) a sulfonyldiazomethane compound capable ofgenerating an acid upon exposure to radiation represented by the generalformula (1) or (1a), and (F) an organic solvent;

2) a chemically amplified positive working resist composition of 1)further comprising (C) a photoacid generator capable of generating anacid upon exposure to radiation other than component (B);

3) a chemically amplified positive working resist composition of 1) or2) further comprising (D) a basic compound;

4) a chemically amplified positive working resist composition of 1) to3) further comprising (E) an organic acid derivative;

5) a chemically amplified positive working resist composition of 1) to4) further comprising (G) a compound with a molecular weight of up to3,000 which changes its solubility in an alkaline developer under theaction of an acid;

6) a chemically amplified negative working resist composition comprising(B) a sulfonyldiazomethane compound capable of generating an acid uponexposure to radiation represented by the general formula (1) or (1a),(F) an organic solvent, (H) an alkali-soluble resin, and (I) an acidcrosslinking agent capable of forming a crosslinked structure under theaction of an acid;

7) a chemically amplified negative working resist composition of 6)further comprising (C) another photoacid generator;

8) a chemically amplified negative working resist composition of 6) or7) further comprising (D) a basic compound; and

9) a chemically amplified negative working resist composition of 6) to8) further comprising (J) an alkali soluble compound having a molecularweight of up to 2,500; but not limited thereto.

Now the respective components are described in detail.

Component (A)

Component (A) is a resin which changes its solubility in an alkalinedeveloper solution under the action of an acid. It is preferably, thoughnot limited thereto, an alkali-soluble resin having phenolic hydroxyland/or carboxyl groups in which some or all of the phenolic hydroxyland/or carboxyl groups are protected with acid-labile protective groupshaving a C—O—C linkage.

The alkali-soluble resins having phenolic hydroxyl and/or carboxylgroups include homopolymers and copolymers of p-hydroxystyrene,m-hydroxystyrene, α-methyl-p-hydroxystyrene, 4-hydroxy-2-methylstyrene,4-hydroxy-3-methylstyrene, hydroxyindene, methacrylic acid and acrylicacid, and such copolymers having a carboxylic derivative or diphenylethylene introduced at their terminus.

Also included are copolymers in which units free of alkali-soluble sitessuch as styrene, α-methylstyrene, acrylate, methacrylate, hydrogenatedhydroxystyrene, maleic anhydride, maleimide, substituted orunsubstituted indene are introduced in addition to the above-describedunits in such a proportion that the solubility in an alkaline developermay not be extremely reduced. Substituents on the acrylates andmethacrylates may be any of the substituents which do not undergoacidolysis. Exemplary substituents are straight, branched or cyclic C₁₋₈alkyl groups and aromatic groups such as aryl groups, but not limitedthereto.

Examples of the alkali-soluble resins or polymers are given below. Thesepolymers may also be used as the material from which the resin (A) whichchanges its solubility in an alkaline developer under the action of anacid is prepared and as the alkali-soluble resin which serves ascomponent (H) to be described later. Examples includepoly(p-hydroxystyrene), poly(m-hydroxystyrene),poly(4-hydroxy-2-methylstyrene), poly(4-hydroxy-3-methylstyrene),poly(α-methyl-p-hydroxystyrene), partially hydrogenated p-hydroxystyrenecopolymers, p-hydroxystyrene-α-methyl-p-hydroxystyrene copolymers,p-hydroxystyrene-α-methylstyrene copolymers, p-hydroxystyrene-styrenecopolymers, p-hydroxystyrene-m-hydroxystyrene copolymers,p-hydroxystyrene-styrene copolymers, p-hydroxystyrene-indene copolymers,p-hydroxystyrene-acrylic acid copolymers, p-hydroxystyrene-methacrylicacid copolymers, p-hydroxystyrene-methyl acrylate copolymers,p-hydroxystyrene-acrylic acid-methyl methacrylate copolymers,p-hydroxystyrene-methyl methacrylate copolymers,p-hydroxystyrene-methacrylic acid-methyl methacrylate copolymers,poly(methacrylic acid), poly(acrylic acid), acrylic acid-methyl acrylatecopolymers, methacrylic acid-methyl methacrylate copolymers, acrylicacid-maleimide copolymers, methacrylic acid-maleimide copolymers,p-hydroxystyrene-acrylic acid-maleimide copolymers, andp-hydroxystyrene-methacrylic acid-maleimide copolymers, but are notlimited to these combinations.

Preferred are poly(p-hydroxystyrene), partially hydrogenatedp-hydroxystyrene copolymers, p-hydroxystyrene-styrene copolymers,p-hydroxystyrene-indene copolymers, p-hydroxystyrene-acrylic acidcopolymers, and p-hydroxystyrene-methacrylic acid copolymers.

Alkali-soluble resins comprising units of the following formula (2),(2′) or (2″) are especially preferred.

Herein R⁴ is hydrogen or methyl, R⁵ is a straight, branched or cyclicalkyl group of 1 to 8 carbon atoms, x is 0 or a positive integer, y is apositive integer, satisfying x+y≦5, M and N are positive integers,satisfying 0<N/(M+N)≦0.5, and A and B are positive integers, and C is 0or a positive integer, satisfying 0<B/(A+B+C)≦0.5.

The polymer of formula (2″) can be synthesized, for example, byeffecting thermal polymerization of an acetoxystyrene monomer, atertiary alkyl (meth)acrylate monomer and an indene monomer in anorganic solvent in the presence of a radical initiator, and subjectingthe resulting polymer to alkaline hydrolysis in an organic solvent fordeblocking the acetoxy group, for thereby forming a ternary copolymer ofhydroxystyrene, tertiary alkyl (meth)acrylate and indene. The organicsolvent used during polymerization is exemplified by toluene, benzene,tetrahydrofuran, diethyl ether and dioxane. Exemplary polymerizationinitiators include 2,2′-azobisisobutyronitrile,2,2′-azobis(2,4-dimethylvaleronitrile),dimethyl-2,2-azobis(2-methylpropionate), benzoyl peroxide, and lauroylperoxide. Polymerization is preferably effected while heating at 50 to80° C. The reaction time is usually about 2 to 100 hours, preferablyabout 5 to 20 hours. Aqueous ammonia, triethylamine or the like may beused as the base for the alkaline hydrolysis. For the alkalinehydrolysis, the temperature is usually −20° C. to 100° C., preferably 0°C. to 60° C., and the time is about 0.2 to 100 hours, preferably about0.5 to 20 hours.

Also included are polymers having the dendritic or hyperbranched polymerstructure of formula (2″′) below.

Herein ZZ is a divalent organic group selected from among CH₂, CH(OH),CR⁵(OH), C═O and C(OR⁵)(OH) or a trivalent organic group represented by—C(OH)═. Subscript F, which may be identical or different, is a positiveinteger, and H is a positive integer, satisfying 0.001≦H/(H+F)≦0.1, andXX is 1 or 2. R⁴, R⁵, x and y are as defined above.

The dendritic or hyperbranched polymer of phenol derivative can besynthesized by effecting living anion polymerization of a polymerizablemonomer such as 4-tert-butoxystyrene and reacting a branching monomersuch as chloromethylstyrene as appropriate during the living anionpolymerization.

For the detail of synthesis, reference is made to JP-A 2000-344836.

The alkali-soluble resins or polymers should preferably have a weightaverage molecular weight (Mw) of 3,000 to 100,000. Many polymers with Mwof less tan 3,000 do not perform well and are poor in heat resistanceand film formation. Many polymers with Mw of more than 100,000 give riseto a problem with respect to dissolution in the resist solvent anddeveloper. The polymer should also preferably have a dispersity (Mw/Mn)of up to 3.5, and more preferably up to 1.5. With a dispersity of morethan 3.5, resolution is low in many cases. Although the preparationmethod is not critical, a poly(p-hydroxystyrene) or similar polymer witha low dispersity or narrow dispersion can be synthesized by living anionpolymerization.

In the resist composition using the sulfonyldiazomethane of formula (1),a resin having such substituent groups with C—O—C linkages (acid labilegroups) that the solubility in an alkaline developer changes as a resultof severing of the C—O—C linkages under the action of an acid,especially an alkali-soluble resin as mentioned above is preferably usedas component (A). Especially preferred is a polymer comprising recurringunits of the above formula (2) and containing phenolic hydroxyl groupsin which hydrogen atoms of the phenolic hydroxyl groups are substitutedwith acid labile groups of one or more types in a proportion of morethan 0 mol % to 80 mol % on the average of the entire hydrogen atoms ofthe phenolic hydroxyl group, the polymer having a weight averagemolecular weight of 3,000 to 100,000.

Also preferred is a polymer comprising recurring units of the aboveformula (2′), that is, a copolymer comprising p-hydroxystyrene and/orα-methyl-p-hydroxystyrene and acrylic acid and/or methacrylic acid,wherein some of the hydrogen atoms of the carboxyl groups of acrylicacid and/or methacrylic acid are substituted with acid labile groups ofone or more types, and the units based on acrylate and/or methacrylateare contained in a proportion of more than 0 mol % to 50 mol %, on theaverage, of the copolymer, and wherein some of the hydrogen atoms of thephenolic hydroxyl groups of p-hydroxystyrene and/orα-methyl-p-hydroxystyrene may be substituted with acid labile groups ofone or more types. In the preferred copolymer, the units based onacrylate and/or methacrylate having acid labile groups substitutedthereon and optionally the units based on p-hydroxystyrene and/orα-methyl-p-hydroxystyrene having acid labile groups substituted thereonare contained in a proportion of more than 0 mol % to 80 mol %, on theaverage, of the copolymer.

Alternatively, a polymer comprising recurring units of the above formula(2″), that is, a copolymer comprising p-hydroxystyrene and/orα-methyl-p-hydroxystyrene and substituted and/or unsubstituted indene,is preferred wherein some of the hydrogen atoms of the phenolic hydroxylgroups of p-hydroxystyrene and/or α-methyl-p-hydroxystyrene aresubstituted with acid labile groups of one or more types, and some ofthe hydrogen atoms of the carboxyl groups of acrylic acid and/ormethacrylic acid are substituted with acid labile groups of one or moretypes. Where the substituted indene has hydroxyl groups, some of thehydrogen atoms of these hydroxyl groups may be substituted with acidlabile groups of one or more types. In the preferred copolymer, theunits based on p-hydroxystyrene and/or α-methyl-p-hydroxystyrene havingacid labile groups substituted thereon, the units based on acrylic acidand/or methacrylic acid having acid labile groups substituted thereon,and the units based on indene having acid labile groups substitutedthereon are contained in a proportion of more than 0 mol % to 80 mol %,on the average, of the copolymer.

Exemplary and preferred such polymers are polymers or high molecularweight compounds comprising recurring units represented by the followinggeneral formula (2a), (2a′) or (2a″) and having a weight averagemolecular weight of 3,000 to 100,000.

Herein, R⁴ is hydrogen or methyl. R⁵ is a straight, branched or cyclicalkyl group of 1 to 8 carbon atoms. Letter x is 0 or a positive integer,and y is a positive integer, satisfying x+y≦5. R⁶ is an acid labilegroup. S and T are positive integers, satisfying 0<T/(S+T)≦0.8. R^(6a)is hydrogen or an acid labile group, at least some of the R^(6a) groupsare acid labile groups. M and N are positive integers, L is 0 or apositive integer, satisfying 0<N/(M+N+L)≦0.5 and 0<(N+L)/(M+N+L)≦0.5.The letter yy is 0 or a positive integer, satisfying x+yy≦5. A and B arepositive integers, C, D and E each are 0 or a positive integer,satisfying 0<(B+E)/(A+B+C+D+E)≦0.5 and 0<(C+D+E)/(A+B+C+D+E)≦0.8.

R⁵ stands for straight, branched or cyclic C₁₋₈ alkyl groups, forexample, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl,tert-butyl, cyclohexyl and cyclopentyl.

With respect to the acid labile groups, where some of the phenolichydroxyl groups and some or all of the carboxyl groups in thealkali-soluble resin are protected with acid labile groups having C—O—Clinkages, the acid labile groups are selected from a variety of suchgroups. The preferred acid labile groups are groups of the followinggeneral formulae (4) to (7), tertiary alkyl groups of 4 to 20 carbonatoms, preferably 4 to 15 carbon atoms, trialkylsilyl groups whose alkylgroups each have 1 to 6 carbon atoms, oxoalkyl groups of 4 to 20 carbonatoms, or aryl-substituted alkyl groups of 7 to 20 carbon atoms.

Herein R¹⁰ and R¹¹ are independently hydrogen or straight, branched orcyclic alkyl groups of 1 to 18 carbon atoms, preferably 1 to 10 carbonatoms, for example, methyl, ethyl, propyl, isopropyl, n-butyl,sec-butyl, tert-butyl, cyclopentyl, cyclohexyl, 2-ethylhexyl andn-octyl. R¹² is a monovalent hydrocarbon group of 1 to 18 carbon atoms,preferably 1 to 10 carbon atoms, which may have a hetero atom (e.g.,oxygen atom), for example, straight, branched or cyclic alkyl groups,and such groups in which some hydrogen atoms are substituted withhydroxyl, alkoxy, oxo, amino or alkylamino groups. Illustrative examplesof the substituted alkyl groups are given below.

A pair of R¹⁰ and R¹¹, a pair of R¹⁰ and R¹², or a pair of R¹¹ and R¹²,taken together, may form a ring. Each of R¹⁰, R¹¹ and R¹² is a straightor branched alkylene group of 1 to 18 carbon atoms, preferably 1 to 10carbon atoms, when they form a ring.

R¹³ is a tertiary alkyl group of 4 to 20 carbon atoms, preferably 4 to15 carbon atoms, a trialkylsilyl group whose alkyl groups each have 1 to6 carbon atoms, an oxoalkyl group of 4 to 20 carbon atoms or a group offormula (4). Exemplary tertiary alkyl groups are tert-butyl, tert-amyl,1,1-diethylpropyl, 1-ethylcyclopentyl, 1-butylcyclopentyl,1-ethylcyclohexyl, 1-butylcyclohexyl, 1-ethyl-2-cyclopentenyl,1-ethyl-2-cyclohexenyl, 2-methyl-2-adamantyl, 2-ethyl-2-adamantyl and1-adamantyl-1-methylethyl. Exemplary trialkylsilyl groups aretrimethylsilyl, triethylsilyl, and dimethyl-tert-butylsilyl. Exemplaryoxoalkyl groups are 3-oxocyclohexyl, 4-methyl-2-oxooxan-4-yl, and5-methyl-5-oxooxolan-4-yl. Letter z is an integer of 0 to 6.

R¹⁴ is a straight, branched or cyclic alkyl group of 1 to 8 carbon atomsor substituted or unsubstituted aryl group of 6 to 20 carbon atoms.Exemplary straight, branched or cyclic alkyl groups include methyl,ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, tert-amyl,n-pentyl, n-hexyl, cyclopentyl, cyclohexyl, cyclopentylmethyl,cyclopentylethyl, cyclohexylmethyl and cyclohexylethyl. Exemplarysubstituted or unsubstituted aryl groups include phenyl, methylphenyl,naphthyl, anthryl, phenanthryl, and pyrenyl. Letter h is equal to 0 or1, i is equal to 0, 1, 2 or 3, satisfying 2h+i=2 or 3.

R¹⁵ is a straight, branched or cyclic alkyl group of 1 to 8 carbon atomsor substituted or unsubstituted aryl group of 6 to 20 carbon atoms,examples of which are as exemplified for R¹⁴. R¹⁶ to R²⁵ areindependently hydrogen or monovalent hydrocarbon groups of 1 to 15carbon atoms which may contain a hetero atom, for example, straight,branched or cyclic alkyl groups such as methyl, ethyl, propyl,isopropyl, n-butyl, sec-butyl, tert-butyl, tert-amyl, n-pentyl, n-hexyl,n-octyl, n-nonyl, n-decyl, cyclopentyl, cyclohexyl, cyclopentylmethyl,cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl,and cyclohexylbutyl, and substituted ones of these groups in which somehydrogen atoms are substituted with hydroxyl, alkoxy, carboxy,alkoxycarbonyl, oxo, amino, alkylamino, cyano, mercapto, alkylthio, andsulfo groups. R¹⁶ to R²⁵, for example, a pair of R¹⁶ and R¹⁷, a pair ofR¹⁶ and R¹⁸, a pair of R¹⁷ and R¹⁹, a pair of R¹⁸ and R¹⁹, a pair of R²⁰and R²¹, or a pair of R²² and R²³, taken together, may form a ring. WhenR¹⁶ to R²⁶ form a ring, they are divalent hydrocarbon groups of 1 to 15carbon atoms which may contain a hetero atom, examples of which are theabove-exemplified monovalent hydrocarbon groups with one hydrogen atomeliminated. Also, two of R¹⁶ to R²⁵ which are attached to adjacentcarbon atoms (for example, a pair of R¹⁶ and R¹⁸, a pair of R¹⁸ and R²⁴,or a pair of R²² and R²⁴) may directly bond together to form a doublebond.

Of the acid labile groups of formula (4), illustrative examples of thestraight or branched groups are given below.

Of the acid labile groups of formula (4), illustrative examples of thecyclic groups include tetrahydrofuran-2-yl,2-methyltetrahydrofuran-2-yl, tetrahydropyran-2-yl and2-methyltetrahydropyran-2-yl.

Illustrative examples of the acid labile groups of formula (5) includetert-butoxycarbonyl, tert-butoxycarbonylmethyl, tert-amyloxycarbonyl,tert-amyloxycarbonyl-methyl, 1,1-diethylpropyloxycarbonyl,1,1-diethylpropyloxycarbonylmethyl, 1-ethylcyclopentyloxycarbonyl,1-ethylcyclopentyloxycarbonylmethyl, 1-ethyl-2-cyclopentenyloxycarbonyl,1-ethyl-2-cyclopentenyloxycarbonylmethyl, 1-ethoxyethoxycarbonylmethyl,2-tetrahydropyranyloxycarbonylmethyl, and2-tetrahydrofuranyloxycarbonylmethyl.

Illustrative examples of the acid labile groups of formula (6) include1-methylcyclopentyl, 1-ethylcyclopentyl, 1-n-propylcyclopentyl,1-isopropylcyclopentyl, 1-n-butylcyclopentyl, 1-sec-butylcyclopentyl,1-methylcyclohexyl, 1-ethylcyclohexyl, 3-methyl-1-cyclopenten-3-yl,3-ethyl-1-cyclopenten-3-yl, 3-methyl-1-cyclohexen-3-yl,3-ethyl-1-cylclohexen-3-yl, and 1-cyclohexyl-cyclopentyl.

Illustrative examples of the acid labile groups of formula (7) are givenbelow.

Exemplary of the tertiary alkyl group of 4 to 20 carbon atoms,preferably 4 to 15 carbon atoms, are tert-butyl, tert-amyl,3-ethyl-3-pentyl and dimethylbenzyl.

Exemplary of the trialkylsilyl groups whose alkyl groups each have 1 to6 carbon atoms are trimethylsilyl, triethylsilyl, andtert-butyldimethylsilyl.

Exemplary of the oxoalkyl groups of 4 to 20 carbon atoms are3-oxocyclohexyl and groups represented by the following formulae.

Exemplary of the aryl-substituted alkyl groups of 7 to 20 carbon atomsare benzyl, methylbenzyl, dimethylbenzyl, diphenylmethyl, and1,1-diphenylethyl.

In the resist composition comprising the sulfonyldiazomethane as aphotoacid generator, the resin (A) which changes its solubility in analkaline developer under the action of an acid may be the polymer offormula (2) or (2′), (2″) or (2″′) in which some of the hydrogen atomsof the phenolic hydroxyl groups are crosslinked within a molecule and/orbetween molecules, in a proportion of more than 0 mol % to 50 mol %, onthe average, of the entire phenolic hydroxyl groups on the polymer, withcrosslinking groups having C—O—C linkages represented by the followinggeneral formula (3). With respect to illustrative examples and synthesisof polymers crosslinked with acid labile groups, reference should bemade to JP-A 11-190904.

Herein, each of R⁷ and R⁸ is hydrogen or a straight, branched or cyclicalkyl group of 1 to 8 carbon atoms, or R⁷ and R⁸, taken together, mayform a ring, and each of R⁷ and R⁸ is a straight or branched alkylenegroup of 1 to 8 carbon atoms when they form a ring. R⁹ is a straight,branched or cyclic alkylene group of 1 to 10 carbon atoms. Letter “b” is0 or an integer of 1 to 10. AA is an a-valent aliphatic or alicyclicsaturated hydrocarbon group, aromatic hydrocarbon group or heterocyclicgroup of 1 to 50 carbon atoms, which may be separated by a hetero atomand in which some of the hydrogen atom attached to carbon atoms may besubstituted with hydroxyl, carboxyl, carbonyl or halogen. Letter “a” isan integer of 1 to 7.

Preferably in formula (3), R⁷ is methyl, R⁸ is hydrogen, a is 1, b is 0,and AA is ethylene, 1,4-butylene or 1,4-cyclohexylene.

It is noted that these polymers which are crosslinked within themolecule or between molecules with crosslinking groups having C—O—Clinkages can be synthesized by reacting a corresponding non-crosslinkedpolymer with an alkenyl ether in the presence of an acid catalyst in aconventional manner.

If decomposition of other acid labile groups proceeds under acidcatalyst conditions, the end product can be obtained by once reactingthe alkenyl ether with hydrochloric acid or the like for conversion to ahalogenated alkyl ether and reacting it with the polymer under basicconditions in a conventional manner.

Illustrative, non-limiting, examples of the alkenyl ether includeethylene glycol divinyl ether, triethylene glycol divinyl ether,1,2-propanediol divinyl ether, 1,3-propanediol divinyl ether,1,3-butanediol divinyl ether, 1,4-butanediol divinyl ether, neopentylglycol divinyl ether, trimethylolpropane trivinyl ether,trimethylolethane trivinyl ether, hexanediol divinyl ether, and1,4-cyclohexanediol divinyl ether.

In the chemical amplification type positive resist composition, theresin used as component (A) is as described above while the preferredacid labile groups to be substituted for phenolic hydroxyl groups are1-ethoxyethyl, 1-ethoxypropyl, tetrahydrofuranyl, tetrahydropyranyl,tert-butyl, tert-amyl, 1-ethylcyclohexyloxycarbonylmethyl,tert-butoxycarbonyl, tert-butoxycarbonylmethyl, and substituents offormula (3) wherein R⁷ is methyl, R⁸ is hydrogen, a is 1, b is equal to0, and AA is ethylene, 1,4-butylene or 1,4-cyclohexylene. Alsopreferably, the hydrogen atoms of carboxyl groups of methacrylic acid oracrylic acid are protected with substituent groups as typified bytert-butyl, tert-amyl, 2-methyl-2-adamantyl, 2-ethyl-2-adamantyl,1-ethylcyclopentyl, 1-ethylcyclohexyl, 1-cyclohexylcyclopentyl,1-ethylnorbornyl, tetrahydrofuranyl and tetrahydropyranyl.

In a single polymer, these substituents may be incorporated alone or inadmixture of two or more types. A blend of two or more polymers havingsubstituents of different types is also acceptable.

The percent proportion of these substituents substituting for phenol andcarboxyl groups in the polymer is not critical. Preferably the percentsubstitution is selected such that when a resist composition comprisingthe polymer is applied onto a substrate to form a coating, the unexposedarea of the coating may have a dissolution rate of 0.01 to 10 Å/sec in a2.38% tetramethylammonium hydroxide (TMAH) developer.

On use of a polymer containing a greater proportion of carboxyl groupswhich can reduce the alkali dissolution rate, the percent substitutionmust be increased or non-acid-decomposable substituents to be describedlater must be introduced.

When acid labile groups for intramolecular and/or intermolecularcrosslinking are to be introduced, the percent proportion ofcrosslinking substituents is preferably up to 20 mol %, more preferablyup to 10 mol %, based on the entire hydrogen atoms of phenolic hydroxylgroups. If the percent substitution of crosslinking substituents is toohigh, crosslinking results in a higher molecular weight which canadversely affect dissolution, stability and resolution. It is alsopreferred to further introduce another non-crosslinking acid labilegroup into the crosslinked polymer at a percent substitution of up to 10mol % for adjusting the dissolution rate to fall within the above range.

In the case of poly(p-hydroxystyrene), the optimum percent substitutiondiffers between a substituent having a strong dissolution inhibitoryaction such as a tert-butoxycarbonyl group and a substituent having aweak dissolution inhibitory action such as an acetal group although theoverall percent substitution is preferably 10 to 40 mol %, morepreferably 20 to 30 mol %, based on the entire hydrogen atoms ofphenolic hydroxyl groups in the polymer.

Polymers having such acid labile groups introduced therein shouldpreferably have a weight average molecular weight (Mw) of 3,000 to100,000. With a Mw of less than 3,000, polymers would perform poorly andoften lack heat resistance and film formability. Polymers with a Mw ofmore than 100,000 would be less soluble in a developer and a resistsolvent.

Where non-crosslinking acid labile groups are introduced, the polymershould preferably have a dispersity (Mw/Mn) of up to 3.5, preferably upto 1.5. A polymer with a dispersity of more than 3.5 often results in alow resolution. Where crosslinking acid labile groups are introduced,the starting alkali-soluble resin should preferably have a dispersity(Mw/Mn) of up to 1.5, and the dispersity is kept at 3 or lower evenafter protection with crosslinking acid labile groups. If the dispersityis higher than 3, dissolution, coating, storage stability and/orresolution is often poor.

To impart a certain function, suitable substituent groups may beintroduced into some of the phenolic hydroxyl and carboxyl groups on theacid labile group-protected polymer. Exemplary are substituent groupsfor improving adhesion to the substrate, non-acid-labile groups foradjusting dissolution in an alkali developer, and substituent groups forimproving etching resistance. Illustrative, non-limiting, substituentgroups include 2-hydroxyethyl, 2-hydroxypropyl, methoxymethyl,methoxycarbonyl, ethoxycarbonyl, methoxycarbonylmethyl,ethoxycarbonylmethyl, 4-methyl-2-oxo-4-oxoranyl,4-methyl-2-oxo-4-oxanyl, methyl, ethyl, propyl, n-butyl, sec-butyl,acetyl, pivaloyl, adamantyl, isoboronyl, and cyclohexyl.

In the resist composition of the invention, the above-described resin isadded in any desired amount, and usually 65 to 99 parts by weight,preferably 70 to 98 parts by weight per 100 parts by weight of thesolids in the composition. The term “solids” is used to encompass allcomponents in the resist composition excluding the solvent.

Illustrative examples of the sulfonyldiazomethane compounds of formulae(1) and (1a) as the photoacid generator (B) are as described above.Listing again, examples of bilaterally symmetric bissulfonyldiazomethaneinclude bis(4-n-butylphenylsulfonyl)diazomethane,bis(4-n-pentylphenylsulfonyl)diazomethane,bis(4-n-hexylphenyl-sulfonyl)diazomethane,bis(4-n-heptylphenylsulfonyl)diazomethane,bis(4-n-octylphenylsulfonyl)diazomethane,bis(4-n-nonylphenylsulfonyl)diazomethane,bis(4-n-decylphenyl-sulfonyl)diazomethane,bis(4-n-undecylphenylsulfonyl)diazo-methane,bis(4-n-dodecylphenylsulfonyl)diazomethane,bis(4-(n-butyloxy)phenylsulfonyl)diazomethane,bis(4-(n-pentyloxy)phenylsulfonyl)diazomethane,bis(4-(n-hexyloxy)-phenylsulfonyl)diazomethane,bis(4-(n-heptyloxy)phenyl-sulfonyl)diazomethane,bis(4-(n-octyloxy)phenylsulfonyl)-diazomethane,bis(4-(n-nonyloxy)phenylsulfonyl)diazomethane,bis(4-(n-decyloxy)phenylsulfonyl)diazomethane,bis(4-(n-undecyloxy)phenylsulfonyl)diazomethane,bis(4-(n-dodecyloxy)phenylsulfonyl)diazomethane,bis(3-methyl-4-(n-butyloxy)phenylsulfonyl)diazomethane,bis(3-methyl-4-(n-pentyloxy)phenylsulfonyl)diazomethane,bis(3-methyl-4-(n-hexyloxy)phenylsulfonyl)diazomethane,bis(3-methyl-4-(n-heptyloxy)phenylsulfonyl)diazomethane,bis(3-methyl-4-(n-octyloxy)phenylsulfonyl)diazomethane,bis(3-methyl-4-(n-nonyloxy)phenylsulfonyl)diazomethane,bis(3-methyl-4-(n-decyloxy)phenylsulfonyl)diazomethane,bis(3-methyl-4-(n-undecyloxy)phenylsulfonyl)diazomethane,bis(3-methyl-4-(n-dodecyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-4-(n-butyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-4-(n-pentyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-4-(n-hexyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-4-(n-heptyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-4-(n-octyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-4-(n-nonyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-4-(n-decyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-4-(n-undecyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-4-(n-dodecyloxy)phenylsulfonyl)diazomethane,bis(3,5-dimethyl-4-(n-butyloxy)phenylsulfonyl)diazomethane,bis(3,5-dimethyl-4-(n-pentyloxy)phenylsulfonyl)diazomethane,bis(3,5-dimethyl-4-(n-hexyloxy)phenylsulfonyl)diazomethane,bis(3,5-dimethyl-4-(n-heptyloxy)phenylsulfonyl)diazomethane,bis(3,5-dimethyl-4-(n-octyloxy)phenylsulfonyl)diazomethane,bis(3,5-dimethyl-4-(n-nonyloxy)phenylsulfonyl)diazomethane,bis(3,5-dimethyl-4-(n-decyloxy)phenylsulfonyl)diazomethane,bis(3,5-dimethyl-4-(n-undecyloxy)phenylsulfonyl)diazomethane,bis(3,5-dimethyl-4-(n-dodecyloxy)phenylsulfonyl)diazomethane,bis(5-isopropyl-2-methyl-4-(n-butyloxy)phenyl-sulfonyl)diazomethane,bis(5-isopropyl-2-methyl-4-(n-pentyloxy)phenylsulfonyl)diazomethane,bis(5-isopropyl-2-methyl-4-(n-hexyloxy)phenylsulfonyl)diazomethane,bis(5-isopropyl-2-methyl-4-(n-heptyloxy)phenylsulfonyl)diazomethane,bis(5-isopropyl-2-methyl-4-(n-octyloxy)phenylsulfonyl)diazomethane,bis(5-isopropyl-2-methyl-4-(n-nonyloxy)phenylsulfonyl)diazomethane,bis(5-isopropyl-2-methyl-4-(n-decyloxy)phenylsulfonyl)diazomethane,bis(5-isopropyl-2-methyl-4-(n-undecyloxy)phenylsulfonyl)diazomethane,andbis(5-isopropyl-2-methyl-4-(n-dodecyloxy)phenylsulfonyl)diazomethane;

examples of bilaterally asymmetric sulfonyldiazomethane include(4-(n-hexyloxy)phenylsulfonyl)(methylsulfonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(tert-butylsulfonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(cyclohexylsulfonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(benzenesulfonyl)diazomethane,(4-(n-hexyloxy)-phenylsulfonyl)(p-toluenesulfonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(2,4-dimethylphenylsulfonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(4-tert-butylphenylsulfonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(4-tert-butoxyphenylsulfonyl)diazomethane,(4-(n-octyloxy)phenylsulfonyl)(methylsulfonyl)diazomethane,(4-(n-octyloxy)phenylsulfonyl)(tert-butylsulfonyl)diazomethane,(4-(n-octyloxy)phenylsulfonyl)(cyclohexylsulfonyl)diazomethane,(4-(n-octyloxy)phenylsulfonyl)(benzenesulfonyl)diazomethane,(4-(n-octyloxy)phenylsulfonyl)(p-toluenesulfonyl)diazomethane,(4-(n-octyloxy)phenylsulfonyl)(2,4-dimethylphenylsulfonyl)diazomethane,(4-(n-octyloxy)phenylsulfonyl)(4-tert-butylphenylsulfonyl)diazomethane,and(4-(n-octyloxy)phenylsulfonyl)(4-tert-butoxyphenylsulfonyl)diazomethane;

examples of the sulfonylcarbonyldiazomethane include(4-(n-hexyloxy)phenylsulfonyl)(methylcarbonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(tert-butylcarbonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(cyclohexylcarbonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(benzoyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(p-toluenecarbonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(2,4-dimethyl-phenylcarbonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(4-tert-butylphenylcarbonyl)diazomethane,and(4-(n-hexyloxy)phenylsulfonyl)(4-tert-butoxyphenylcarbonyl)diazomethane,etc.

Of these, preferred are bis(4-n-hexylphenylsulfonyl)diazomethane,bis(4-n-pentylphenylsulfonyl)diazomethane,bis(4-n-octylphenylsulfonyl)diazomethane,bis(4-(n-pentyloxy)phenylsulfonyl)diazomethane,bis(4-(n-hexyloxy)-phenylsulfonyl)diazomethane,bis(4-(n-heptyloxy)phenyl-sulfonyl)diazomethane,bis(4-(n-octyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-4-(n-pentyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-4-(n-hexyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-4-(n-heptyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-4-(n-octyloxy)phenylsulfonyl)diazomethane,bis(3,5-dimethyl-4-(n-hexyloxy)phenyl-sulfonyl)diazomethane,bis(3,5-dimethyl-4-(n-heptyloxy)-phenylsulfonyl)diazomethane,bis(3,5-dimethyl-4-(n-octyloxy)phenylsulfonyl)diazomethane,(4-(n-hexyloxy)phenyl-sulfonyl)(cyclohexylsulfonyl)diazomethane,(4-(n-hexyloxy)-phenylsulfonyl)(benzenesulfonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(p-toluenesulfonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(2,4-dimethylphenylsulfonyl)diazomethane,(4-(n-hexyloxy)phenylsulfonyl)(4-tert-butyl-phenylsulfonyl)diazomethane,and the like; and most preferred arebis(4-(n-hexyloxy)phenylsulfonyl)diazomethane,bis(2-methyl-4-(n-hexyloxy)phenylsulfonyl)diazomethane,bis(2,5-dimethyl-4-(n-hexyloxy)phenylsulfonyl)diazomethane,bis(3,5-dimethyl-4-(n-hexyloxy)phenylsulfonyl)diazomethane, andbis(2-methyl-5-isopropyl-4-(n-hexyloxy)phenylsulfonyl)diazomethane.

In the chemical amplification resist composition, an appropriate amountof the sulfonyldiazomethane compound of formula (1) or (1a) added isfrom more than 0 part to 10 parts by weight, and preferably from 1 to 5parts by weight, per 100 parts by weight of the solids in thecomposition. The sulfonyldiazomethane compound is used at least in anamount to generate a sufficient amount of acid to deblock acid labilegroups in the polymer. Too large amounts may excessively reduce thetransmittance of resist film, failing to form a rectangular pattern, andgive rise to problems of abnormal particles and deposits during resiststorage. The photoacid generators may be used alone or in admixture oftwo or more.

Component (C)

In one preferred embodiment, the resist composition further contains (C)a compound capable of generating an acid upon exposure to high energyradiation, that is, a second photoacid generator other than thesulfonyldiazomethane (B). Suitable second photoacid generators includesulfonium salts, iodonium salts, sulfonyldiazomethane andN-sulfonyloxyimide photoacid generators. Exemplary second photoacidgenerators are given below while they may be used alone or in admixtureof two or more.

Sulfonium salts are salts of sulfonium cations with sulfonates.Exemplary sulfonium cations include triphenylsulfonium,(4-tert-butoxyphenyl)diphenylsulfonium,bis(4-tert-butoxyphenyl)phenylsulfonium,tris(4-tert-butoxyphenyl)sulfonium,(3-tert-butoxyphenyl)diphenylsulfonium,bis(3-tert-butoxyphenyl)phenylsulfonium,tris(3-tert-butoxyphenyl)sulfonium,(3,4-di-tert-butoxyphenyl)diphenylsulfonium,bis(3,4-di-tert-butoxyphenyl)phenylsulfonium,tris(3,4-di-tert-butoxyphenyl)sulfonium,diphenyl(4-thiophenoxyphenyl)sulfonium,(4-tert-butoxycarbonylmethyloxyphenyl)diphenylsulfonium,tris(4-tert-butoxy-carbonylmethyloxyphenyl)sulfonium,(4-tert-butoxyphenyl)-bis(4-dimethylaminophenyl)sulfonium,tris(4-dimethylaminophenyl)sulfonium, 2-naphthyldiphenylsulfonium,dimethyl-2-naphthylsulfonium, 4-hydroxyphenyldimethylsulfonium,4-methoxyphenyldimethylsulfonium, trimethylsulfonium,2-oxocyclohexylcyclohexylmethylsulfonium, trinaphthylsulfonium,tribenzylsulfonium, diphenylmethylsulfonium, dimethylphenylsulfonium,and 2-oxo-2-phenylethylthiacyclopentanium. Exemplary sulfonates includetrifluoromethanesulfonate, nonafluorobutanesulfonate,heptadecafluorooctanesulfonate, 2,2,2-trifluoroethanesulfonate,pentafluorobenzenesulfonate, 4-trifluoromethylbenzenesulfonate,4-fluorobenzenesulfonate, mesitylenesulfonate,2,4,6-triisopropylbenzenesulfonate, toluenesulfonate, benzenesulfonate,4-(4′-toluenesulfonyloxy)benzenesulfonate, naphthalenesulfonate,camphorsulfonate, octanesulfonate, dodecylbenzenesulfonate,butanesulfonate, and methanesulfonate. Sulfonium salts based oncombination of the foregoing examples are included.

Iodinium salts are salts of iodonium cations with sulfonates. Exemplaryiodinium cations are aryliodonium cations including diphenyliodinium,bis(4-tert-butylphenyl)iodonium, 4-tert-butoxyphenylphenyliodonium, and4-methoxyphenylphenyliodonium. Exemplary sulfonates includetrifluoromethanesulfonate, nonafluorobutanesulfonate,heptadecafluorooctanesulfonate, 2,2,2-trifluoroethanesulfonate,pentafluorobenzenesulfonate, 4-trifluoromethylbenzenesulfonate,4-fluorobenzenesulfonate, mesitylenesulfonate,2,4,6-triisopropylbenzenesufonate, toluenesulfonate, benzenesulfonate,4-(4-toluenesulfonyloxy)benzenesulfonate, naphthalenesulfonate,camphorsulfonate, octanesulfonate, dodecylbenzenesulfonate,butanesulfonate, and methanesulfonate. Iodonium salts based oncombination of the foregoing examples are included.

Exemplary sulfonyldiazomethane compounds include bissulfonyldiazomethanecompounds and sulfonylcarbonyldiazomethane compounds such asbis(ethylsulfonyl)diazomethane, bis(1-methylpropylsulfonyl)diazomethane,bis(2-methylpropylsulfonyl)diazomethane,bis(1,1-dimethylethylsulfonyl)diazomethane,bis(cyclohexylsulfonyl)diazomethane,bis(perfluoroisopropylsulfonyl)diazomethane,bis(phenylsulfonyl)diazomethane,bis(4-methylphenylsulfonyl)diazomethane,bis(2,4-dimethylphenylsulfonyl)diazomethane,bis(2-naphthylsulfonyl)diazomethane,bis(4-acetyloxyphenylsulfonyl)diazomethane,bis(4-methanesulfonyloxyphenylsulfonyl)diazomethane,bis(4-(4-toluenesulfonyloxy)phenylsulfonyl)diazomethane,4-methylphenylsulfonylbenzoyldiazomethane,tert-butylcarbonyl-4-methylphenylsulfonyldiazomethane,2-naphthylsulfonylbenzoyldiazomethane,4-methylphenylsulfonyl-2-naphthoyldiazomethane,methylsulfonylbenzoyldiazomethane, andtert-butoxycarbonyl-4-methylphenylsulfonyldiazomethane.

N-sulfonyloxyimide photoacid generators include combinations of imideskeletons with sulfonates. Exemplary imide skeletons are succinimide,naphthalene dicarboxylic acid imide, phthalimide, cyclohexyldicarboxylicacid imide, 5-norbornene-2,3-dicarboxylic acid imide, and7-oxabicyclo[2.2.1]-5-heptene-2,3-dicarboxylic acid imide. Exemplarysulfonates include trifluoromethanesulfonate, nonafluorobutanesulfonate,heptadecafluorooctanesulfonate, 2,2,2-trifluoroethanesulfonate,pentafluorobenzenesulfonate, 4-trifluoromethylbenzenesulfonate,4-fluorobenzenesulfonate, mesitylenesulfonate,2,4,6-triisopropylbenzenesulfonate, toluenesulfonate, benzenesulfonate,naphthalenesulfonate, camphorsulfonate, octanesulfonate,dodecylbenzenesulfonate, butanesulfonate, and methanesulfonate.

Benzoinsulfonate photoacid generators include benzoin tosylate, benzoinmesylate, and benzoin butanesulfonate.

Pyrogallol trisulfonate photoacid generators include pyrogallol,fluoroglycine, catechol, resorcinol, hydroquinone, in which all thehydroxyl groups are substituted with trifluoromethanesulfonate,nonafluorobutanesulfonate, heptadecafluorooctanesulfonate,2,2,2-trifluoroethanesulfonate, pentafluorobenzenesulfonate,4-trifluoromethylbenzenesulfonate, 4-fluorobenzenesulfonate,toluenesulfonate, benzenesulfonate, naphthalenesulfonate,camphorsulfonate, octanesulfonate, dodecylbenzenesulfonate,butanesulfonate, and methanesulfonate.

Nitrobenzyl sulfonate photoacid generators include 2,4-dinitrobenzylsulfonate, 2-nitrobenzyl sulfonate, and 2,6-dinitrobenzyl sulfonate,with exemplary sulfonates including trifluoromethanesulfonate,nonafluorobutanesulfonate, heptadecafluorooctanesulfonate,2,2,2-trifluoroethanesulfonate, pentafluorobenzenesulfonate,4-trifluoromethylbenzenesulfonate, 4-fluorobenzenesulfonate,toluenesulfonate, benzenesulfonate, naphthalenesulfonate,camphorsulfonate, octanesulfonate, dodecylbenzenesulfonate,butanesulfonate, and methanesulfonate. Also useful are analogousnitrobenzyl sulfonate compounds in which the nitro group on the benzylside is substituted with a trifluoromethyl group.

Sulfone photoacid generators include bis(phenylsulfonyl)methane,bis(4-methylphenylsulfonyl)methane, bis(2-naphthylsulfonyl)methane,2,2-bis(phenylsulfonyl)propane, 2,2-bis(4-methylphenylsulfonyl)propane,2,2-bis(2-naphthylsulfonyl)propane,2-methyl-2-(p-toluenesulfonyl)propiophenone,2-cyclohexylcarbonyl-2-(p-toluenesulfonyl)propane, and2,4-dimethyl-2-(p-toluenesulfonyl)pentan-3-one.

Photoacid generators in the form of glyoxime derivatives are describedin Japanese Patent No. 2,906,999 and JP-A 9-301948 and includebis-O-(p-toluenesulfonyl)-α-dimethylglyoxime,bis-O-(p-toluenesulfonyl)-α-diphenyl-glyoxime,bis-O-(p-toluenesulfonyl)-α-dicyclohexylglyoxime,bis-O-(p-toluenesulfonyl)-2,3-pentanedioneglyoxime,bis-O-(n-butanesulfonyl)-α-dimethylglyoxime,bis-O-(n-butane-sulfonyl)-α-diphenylglyoxime,bis-O-(n-butanesulfonyl)-α-dicyclohexylglyoxime,bis-O-(methanesulfonyl)-α-dimethylglyoxime,bis-O-(trifluoromethanesulfonyl)-α-dimethylglyoxime,bis-O-(2,2,2-trifluoroethanesulfonyl)-α-dimethylglyoxime,bis-O-(10-camphorsulfonyl)-α-dimethylglyoxime,bis-O-(benzenesulfonyl)-α-dimethylglyoxime,bis-O-(p-fluorobenzenesulfonyl)-α-dimethylglyoxime,bis-O-(p-trifluoromethylbenzenesulfonyl)-α-dimethylglyoxime,bis-O-(xylenesulfonyl)-α-dimethylglyoxime,bis-O-(trifluoromethanesulfonyl)-nioxime,bis-O-(2,2,2-trifluoroethanesulfonyl)-nioxime,bis-O-(10-camphorsulfonyl)-nioxime, bis-O-(benzenesulfonyl)-nioxime,bis-O-(p-fluorobenzenesulfonyl)-nioxime,bis-O-(p-trifluoromethylbenzenesulfonyl)-nioxime, andbis-O-(xylenesulfonyl)-nioxime.

Also included are the oxime sulfonates described in U.S. Pat. No.6,004,724, for example,(5-(4-toluenesulfonyl)oxyimino-5H-thiophen-2-ylidene)phenylacetonitrile,(5-(10-camphorsulfonyl)oxyimino-5H-thiophen-2-ylidene)phenylacetonitrile,(5-n-octanesulfonyloxyimino-5H-thiophen-2-ylidene)phenylacetonitrile,(5-(4-toluenesulfonyl)oxyimino-5H-thiophen-2-ylidene)(2-methylphenyl)acetonitrile,(5-(10-camphorsulfonyl)oxyimino-5H-thiophen-2-ylidene)(2-methylphenyl)acetonitrile,(5-n-octanesulfonyloxyimino-5H-thiophen-2-ylidene)(2-methylphenyl)acetonitrile,etc.

Also included are the oxime sulfonates described in U.S. Pat. No.6,261,738 and JP-A 2000-314956, for example,2,2,2-trifluoro-1-phenyl-ethanone oxime-O-methylsulfonate;2,2,2-trifluoro-1-phenyl-ethanone oxime-O-(10-camphorylsulfonate);2,2,2-trifluoro-1-phenyl-ethanone oxime-O-(4-methoxyphenylsulfonate);2,2,2-trifluoro-1-phenyl-ethanone oxime-O-(1-naphthylsulfonate);2,2,2-trifluoro-1-phenyl-ethanone oxime-O-(2-naphthylsulfonate);2,2,2-trifluoro-1-phenyl-ethanoneoxime-O-(2,4,6-trimethylphenylsulfonate);2,2,2-trifluoro-1-(4-methylphenyl)-ethanoneoxime-O-(10-camphorylsulfonate);2,2,2-trifluoro-1-(4-methylphenyl)-ethanone oxime-O-(methylsulfonate);2,2,2-trifluoro-1-(2-methylphenyl)-ethanoneoxime-O-(10-camphorylsulfonate);2,2,2-trifluoro-1-(2,4-dimethylphenyl)-ethanoneoxime-O-(10-camphorylsulfonate);2,2,2-trifluoro-1-(2,4-dimethylphenyl)-ethanoneoxime-O-(1-naphthylsulfonate);2,2,2-trifluoro-1-(2,4-dimethylphenyl)-ethanoneoxime-O-(2-naphthylsulfonate);2,2,2-trifluoro-1-(2,4,6-trimethylphenyl)-ethanoneoxime-O-(10-camphorylsulfonate);2,2,2-trifluoro-1-(2,4,6-trimethylphenyl)-ethanoneoxime-O-(1-naphthylsulfonate);2,2,2-trifluoro-1-(2,4,6-trimethylphenyl)-ethanoneoxime-O-(2-naphthylsulfonate); 2,2,2-trifluoro-1-(4-methoxyphenyl)ethanone oxime-O-methylsulfonate;2,2,2-trifluoro-1-(4-methylthiophenyl)-ethanone oxime-O-methylsulfonate;2,2,2-trifluoro-1-(3,4-dimethoxyphenyl)-ethanoneoxime-O-methylsulfonate; 2,2,3,3,4,4,4-heptafluoro-1-phenyl-butanoneoxime-O-(10-camphorylsulfonate); 2,2,2-trifluoro-1-(phenyl)-ethanoneoxime-O-methylsulfonate; 2,2,2-trifluoro-1-(phenyl)-ethanoneoxime-O-10-camphorylsulfonate; 2,2,2-trifluoro-1-(phenyl)-ethanoneoxime-O-(4-methoxyphenyl)sulfonate; 2,2,2-trifluoro-1-(phenyl)-ethanoneoxime-O-(1-naphthyl)sulfonate; 2,2,2-trifluoro-1-(phenyl)-ethanoneoxime-O-(2-naphthyl)sulfonate; 2,2,2-trifluoro-1-(phenyl)-ethanoneoxime-O-(2,4,6-trimethylphenyl)sulfonate;2,2,2-trifluoro-1-(4-methylphenyl)-ethanoneoxime-O-(10-camphoryl)sulfonate;2,2,2-trifluoro-1-(4-methylphenyl)-ethanone oxime-O-methylsulfonate;2,2,2-trifluoro-1-(2-methylphenyl)-ethanoneoxime-O-(10-camphoryl)sulfonate;2,2,2-trifluoro-1-(2,4-dimethylphenyl)-ethanoneoxime-O-(1-naphthyl)sulfonate;2,2,2-trifluoro-1-(2,4-dimethylphenyl)-ethanoneoxime-O-(2-naphthyl)sulfonate;2,2,2-trifluoro-1-(2,4,6-trimethylphenyl)-ethanoneoxime-O-(10-camphoryl)sulfonate;2,2,2-trifluoro-1-(2,4,6-trimethylphenyl)-ethanoneoxime-O-(1-naphthyl)sulfonate;2,2,2-trifluoro-1-(2,4,6-trimethylphenyl)-ethanoneoxime-O-(2-naphthyl)sulfonate;2,2,2-trifluoro-1-(4-methoxyphenyl)-ethanone oxime-O-methylsulfonate;2,2,2-trifluoro-1-(4-thiomethylphenyl)-ethanone oxime-O-methylsulfonate;2,2,2-trifluoro-1-(3,4-dimethoxyphenyl)-ethanoneoxime-O-methylsulfonate; 2,2,2-trifluoro-1-(4-methoxyphenyl)-ethanoneoxime-O-(4-methylphenyl)sulfonate;2,2,2-trifluoro-1-(4-methoxyphenyl)-ethanoneoxime-O-(4-methoxyphenyl)sulfonate;2,2,2-trifluoro-1-(4-methoxyphenyl)-ethanoneoxime-O-(4-dodecylphenyl)sulfonate;2,2,2-trifluoro-1-(4-methoxyphenyl)-ethanone oxime-O-octylsulfonate;2,2,2-trifluoro-1-(4-thiomethylphenyl)-ethanoneoxime-O-(4-methoxyphenyl)sulfonate;2,2,2-trifluoro-1-(4-thiomethylphenyl)-ethanoneoxime-O-(4-dodecylphenyl)sulfonate;2,2,2-trifluoro-1-(4-thiomethylphenyl)-ethanone oxime-O-octylsulfonate;2,2,2-trifluoro-1-(4-thiomethylphenyl)-ethanoneoxime-O-(2-naphthyl)sulfonate;2,2,2-trifluoro-1-(2-methylphenyl)-ethanone oxime-O-methylsulfonate;2,2,2-trifluoro-1-(4-methylphenyl)ethanone oxime-O-phenylsulfonate;2,2,2-trifluoro-1-(4-chlorophenyl)-ethanone oxime-O-phenylsulfonate;2,2,3,3,4,4,4-heptafluoro-1-(phenyl)-butanoneoxime-O-(10-camphoryl)sulfonate; 2,2,2-trifluoro-1-naphthyl-ethanoneoxime-O-methylsulfonate; 2,2,2-trifluoro-2-naphthyl-ethanoneoxime-O-methylsulfonate; 2,2,2-trifluoro-1-[4-benzylphenyl]-ethanoneoxime-O-methylsulfonate;2,2,2-trifluoro-1-[4-(phenyl-1,4-dioxa-but-1-yl)phenyl]-ethanoneoxime-O-methylsulfonate; 2,2,2-trifluoro-1-naphthyl-ethanoneoxime-O-propylsulfonate; 2,2,2-trifluoro-2-naphthyl-ethanoneoxime-O-propylsulfonate; 2,2,2-trifluoro-1-[4-benzylphenyl]-ethanoneoxime-O-propylsulfonate;2,2,2-trifluoro-1-[4-methylsulfonylphenyl]-ethanoneoxime-O-propylsulfonate;1,3-bis[1-(4-phenoxyphenyl)-2,2,2-trifluoroethanoneoxime-O-sulfonyl]phenyl;2,2,2-trifluoro-1-[4-methylsulfonyloxyphenyl]-ethanoneoxime-O-propylsulfonate;2,2,2-trifluoro-1-[4-methylcarbonyloxyphenyl]-ethanoneoxime-O-propylsulfonate;2,2,2-trifluoro-1-[6H,7H-5,8-dioxonaphth-2-yl]-ethanoneoxime-O-propylsulfonate;2,2,2-trifluoro-1-[4-methoxycarbonylmethoxyphenyl]-ethanoneoxime-O-propylsulfonate;2,2,2-trifluoro-1-[4-(methoxycarbonyl)-(4-amino-1-oxa-pent-1-yl)-phenyl]-ethanoneoxime-O-propylsulfonate;2,2,2-trifluoro-1-[3,5-dimethyl-4-ethoxyphenyl]-ethanoneoxime-O-propylsulfonate; 2,2,2-trifluoro-1-[4-benzyloxyphenyl]-ethanoneoxime-O-propylsulfonate; 2,2,2-trifluoro-1-[2-thiophenyl]-ethanoneoxime-O-propylsulfonate; and2,2,2-trifluoro-1-[1-dioxa-thiophen-2-yl)]-ethanoneoxime-O-propylsulfonate.

Also included are the oxime sulfonates described in JP-A 9-95479 andJP-A 9-230588 and the references cited therein, for example,α-(p-toluenesulfonyloxyimino)-phenylacetonitrile,α-(p-chlorobenzenesulfonyloxyimino)-phenylacetonitrile,α-(4-nitrobenzenesulfonyloxyimino)-phenylacetonitrile,α-(4-nitro-2-trifluoromethylbenzenesulfonyloxyimino)-phenylacetonitrile,α-(benzenesulfonyloxyimino)-4-chlorophenylacetonitrile,α-(benzenesulfonyloxyimino)-2,4-dichlorophenylacetonitrile,α-(benzenesulfonyloxyimino)-2,6-dichlorophenylacetonitrile,α-(benzenesulfonyloxyimino)-4-methoxyphenylacetonitrile,α-(2-chlorobenzenesulfonyloxyimino)-4-methoxyphenylacetonitrile,α-(benzenesulfonyloxyimino)-2-thienylacetonitrile,α-(4-dodecylbenzenesulfonyloxyimino)-phenylacetonitrile,α-[(4-toluenesulfonyloxyimino)-4-methoxyphenyl]acetonitrile,α-[(dodecylbenzenesulfonyloxyimino)-4-methoxyphenyl]acetonitrile,α-(tosyloxyimino)-3-thienylacetonitrile,α-(methylsulfonyloxyimino)-1-cyclopentenylacetonitrile,α-(ethylsulfonyloxyimino)-1-cyclopentenylacetonitrile,α-(isopropylsulfonyloxyimino)-1-cyclopentenylacetonitrile,α-(n-butylsulfonyloxyimino)-1-cyclopentenylacetonitrile,α-(ethylsulfonyloxyimino)-1-cyclohexenylacetonitrile,α-(isopropylsulfonyloxyimino)-1-cyclohexenylacetonitrile, andα-(n-butylsulfonyloxyimino)-1-cyclohexenylacetonitrile.

Suitable bisoxime sulfonates include those described in JP-A 9-208554,for example,bis(α-(4-toluenesulfonyloxy)imino)-p-phenylenediacetonitrile,bis(α-(benzenesulfonyloxy)imino)-p-phenylenediacetonitrile,bis(α-(methanesulfonyloxy)imino)-p-phenylenediacetonitrile,bis(α-(butanesulfonyloxy)imino)-p-phenylenediacetonitrile,bis(α-(10-camphorsulfonyloxy)imino)-p-phenylenediacetonitrile,bis(a-(4-toluenesulfonyloxy)imino)-p-phenylenediacetonitrile,bis(α-(trifluoromethanesulfonyloxy)imino)-p-phenylenediacetonitrile, bis(α-(4-methoxybenzenesulfonyloxy)imino)-p-phenylenediacetonitrile,bis(α-(4-toluenesulfonyloxy)imino)-m-phenylenediacetonitrile,bis(α-(benzenesulfonyloxy)imino)-m-phenylenediacetonitrile,bis(α-(methanesulfonyloxy)imino)-m-phenylenediacetonitrile,bis(α-(butanesulfonyloxy)imino)-m-phenylenediacetonitrile,bis(α-(10-camphorsulfonyloxy)imino)-m-phenylenediacetonitrile,bis(α-(4-toluenesulfonyloxy)imino)-m-phenylenediacetonitrile,bis(α-(trifluoromethanesulfonyloxy)imino)-m-phenylenediacetonitrile,bis(α-(4-methoxybenzenesulfonyloxy)imino)-m-phenylene-diacetonitrile,etc.

Of these, preferred photoacid generators are sulfonium salts,bissulfonyldiazomethanes, N-sulfonyloxyimides and glyoxime derivatives.More preferred photoacid generators are sulfonium salts,bissulfonyldiazomethanes, and N-sulfonyloxyimides. Typical examplesinclude triphenylsulfonium p-toluenesulfonate, triphenylsulfoniumcamphorsulfonate, triphenylsulfonium pentafluorobenzenesulfonate,triphenylsulfonium nonafluorobutanesulfonate, triphenylsulfonium4-(4′-toluenesulfonyloxy)benzenesulfonate, triphenylsulfonium2,4,6-triisopropylbenzenesulfonate, 4-tert-butoxyphenyldiphenylsulfoniump-toluenesulfonate, 4-tert-butoxyphenyldiphenylsulfoniumcamphorsulfonate, 4-tert-butoxyphenyldiphenylsulfonium4-(4′-toluenesulfonyloxy)benzenesulfonate, tris(4-methylphenyl)sulfoniumcamphorsulfonate, tris(4-tert-butylphenyl)sulfonium camphorsulfonate,bis(tert-butylsulfonyl)diazomethane,bis(cyclohexylsulfonyl)diazomethane,bis(2,4-dimethylphenylsulfonyl)diazomethane,bis(4-tert-butylphenylsulfonyl)diazomethane,N-camphorsulfonyloxy-5-norbornene-2,3-carboxylic acid imide, andN-p-toluenesulfonyloxy-5-norbornene-2,3-carboxylic acid imide.

In the resist composition comprising the sulfonyldiazomethane of formula(1) or (1a) as the first photoacid generator according to the invention,the second photoacid generator (C) may be used in any desired amount aslong as it does not compromise the effects of the sulfonyldiazomethaneof formula (1) or (1a). An appropriate amount of the second photoacidgenerator (C) is 0 to 10 parts, and especially 0 to 5 parts by weightper 100 parts by weight of the solids in the composition. Too high aproportion of the second photoacid generator (C) may give rise toproblems of degraded resolution and foreign matter upon development andresist film peeling. The second photoacid generators may be used aloneor in admixture of two or more. The transmittance of the resist film canbe controlled by using a (second) photoacid generator having a lowtransmittance at the exposure wavelength and adjusting the amount of thephotoacid generator added.

In the resist composition comprising the sulfonyldiazomethane as thephotoacid generator according to the invention, there may be added acompound which is decomposed with an acid to generate an acid, that is,acid-propagating compound. For these compounds, reference should be madeto J. Photopolym. Sci. and Tech., 8, 43-44, 45-46 (1995), and ibid., 9,29-30 (1996).

Examples of the acid-propagating compound includetert-butyl-2-methyl-2-tosyloxymethyl acetoacetate and2-phenyl-2-(2-tosyloxyethyl)-1,3-dioxolane, but are not limited thereto.Of well-known photoacid generators, many of those compounds having poorstability, especially poor thermal stability exhibit an acid-propagatingcompound-like behavior.

In the resist composition comprising the sulfonyldiazomethane as thephotoacid generator according to the invention, an appropriate amount ofthe acid-propagating compound is up to 2 parts, and especially up to 1part by weight per 100 parts by weight of the solids in the composition.Excessive amounts of the acid-propagating compound makes diffusioncontrol difficult, leading to degradation of resolution and patternconfiguration.

Component (D)

The basic compound used as component (D) is preferably a compoundcapable of suppressing the rate of diffusion when the acid generated bythe photoacid generator diffuses within the resist film. The inclusionof this type of basic compound holds down the rate of acid diffusionwithin the resist film, resulting in better resolution. In addition, itsuppresses changes in sensitivity following exposure and reducessubstrate and environment dependence, as well as improving the exposurelatitude and the pattern profile.

Examples of basic compounds include primary, secondary, and tertiaryaliphatic amines, mixed amines, aromatic amines, heterocyclic amines,carboxyl group-bearing nitrogenous compounds, sulfonyl group-bearingnitrogenous compounds, hydroxyl group-bearing nitrogenous compounds,hydroxyphenyl group-bearing nitrogenous compounds, alcoholic nitrogenouscompounds, amide derivatives, and imide derivatives.

Examples of suitable primary aliphatic amines include ammonia,methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine,isobutylamine, sec-butylamine, tert-butylamine, pentylamine,tert-amylamine, cyclopentylamine, hexylamine, cyclohexylamine,heptylamine, octylamine, nonylamine, decylamine, dodecylamine,cetylamine, methylenediamine, ethylenediamine, andtetraethylenepentamine. Examples of suitable secondary aliphatic aminesinclude dimethylamine, diethylamine, di-n-propylamine, diisopropylamine,di-n-butylamine, diisobutylamine, di-sec-butylamine, dipentylamine,dicyclopentylamine, dihexylamine, dicyclohexylamine, diheptylamine,dioctylamine, dinonylamine, didecylamine, didodecylamine, dicetylamine,N,N-dimethylmethylenediamine, N,N-dimethylethylenediamine, andN,N-dimethyltetraethylenepentamine. Examples of suitable tertiaryaliphatic amines include trimethylamine, triethylamine,tri-n-propylamine, triisopropylamine, tri-n-butylamine,triisobutylamine, tri-sec-butylamine, tripentylamine,tricyclopentylamine, trihexylamine, tricyclohexylamine, triheptylamine,trioctylamine, trinonylamine, tridecylamine, tridodecylamine,tricetylamine, N,N,N′,N′-tetramethylmethylenediamine,N,N,N′,N′-tetramethylethylenediamine, andN,N,N′,N′-tetramethyltetraethylenepentamine.

Examples of suitable mixed amines include dimethylethylamine,methylethylpropylamine, benzylamine, phenethylamine, andbenzyldimethylamine. Examples of suitable aromatic and heterocyclicamines include aniline derivatives (e.g., aniline, N-methylaniline,N-ethylaniline, N-propylaniline, N,N-dimethylaniline, 2-methylaniline,3-methylaniline, 4-methylaniline, ethylaniline, propylaniline,trimethylaniline, 2-nitroaniline, 3-nitroaniline, 4-nitroaniline,2,4-dinitroaniline, 2,6-dinitroaniline, 3,5-dinitroaniline, andN,N-dimethyltoluidine), diphenyl(p-tolyl)amine, methyldiphenylamine,triphenylamine, phenylenediamine, naphthylamine, diaminonaphthalene,pyrrole derivatives (e.g., pyrrole, 2H-pyrrole, 1-methylpyrrole,2,4-dimethylpyrrole, 2,5-dimethylpyrrole, and N-methylpyrrole), oxazolederivatives (e.g., oxazole and isooxazole), thiazole derivatives (e.g.,thiazole and isothiazole), imidazole derivatives (e.g., imidazole,4-methylimidazole, and 4-methyl-2-phenylimidazole), pyrazolederivatives, furazan derivatives, pyrroline derivatives (e.g., pyrrolineand 2-methyl-1-pyrroline), pyrrolidine derivatives (e.g., pyrrolidine,N-methylpyrrolidine, pyrrolidinone, and N-methylpyrrolidone),imidazoline derivatives, imidazolidine derivatives, pyridine derivatives(e.g., pyridine, methylpyridine, ethylpyridine, propylpyridine,butylpyridine, 4-(1-butylpentyl)pyridine, dimethylpyridine,trimethylpyridine, triethylpyridine, phenylpyridine,3-methyl-2-phenylpyridine, 4-tert-butylpyridine, diphenylpyridine,benzylpyridine, methoxypyridine, butoxypyridine, dimethoxypyridine,1-methyl-2-pyridone, 4-pyrrolidinopyridine, 1-methyl-4-phenylpyridine,2-(1-ethylpropyl)pyridine, aminopyridine, and dimethylaminopyridine),pyridazine derivatives, pyrimidine derivatives, pyrazine derivatives,pyrazoline derivatives, pyrazolidine derivatives, piperidinederivatives, piperazine derivatives, morpholine derivatives, indolederivatives, isoindole derivatives, 1H-indazole derivatives, indolinederivatives, quinoline derivatives (e.g., quinoline and3-quinolinecarbonitrile), isoquinoline derivatives, cinnolinederivatives, quinazoline derivatives, quinoxaline derivatives,phthalazine derivatives, purine derivatives, pteridine derivatives,carbazole derivatives, phenanthridine derivatives, acridine derivatives,phenazine derivatives, 1,10-phenanthroline derivatives, adeninederivatives, adenosine derivatives, guanine derivatives, guanosinederivatives, uracil derivatives, and uridine derivatives.

Examples of suitable carboxyl group-bearing nitrogenous compoundsinclude aminobenzoic acid, indolecarboxylic acid, and amino acidderivatives (e.g. nicotinic acid, alanine, alginine, aspartic acid,glutamic acid, glycine, histidine, isoleucine, glycylleucine, leucine,methionine, phenylalanine, threonine, lysine,3-aminopyrazine-2-carboxylic acid, and methoxyalanine). Examples ofsuitable sulfonyl group-bearing nitrogenous compounds include3-pyridinesulfonic acid and pyridinium p-toluenesulfonate. Examples ofsuitable hydroxyl group-bearing nitrogenous compounds, hydroxyphenylgroup-bearing nitrogenous compounds, and alcoholic nitrogenous compoundsinclude 2-hydroxypyridine, aminocresol, 2,4-quinolinediol,3-indolemethanol hydrate, monoethanolamine, diethanolamine,triethanolamine, N-ethyldiethanolamine, N,N-diethylethanolamine,triisopropanolamine, 2,2′-iminodiethanol, 2-aminoethanol,3-amino-1-propanol, 4-amino-1-butanol, 4-(2-hydroxyethyl)morpholine,2-(2-hydroxyethyl)pyridine, 1-(2-hydroxyethyl)piperazine,1-[2-(2-hydroxyethoxy)ethyl]-piperazine, piperidine ethanol,1-(2-hydroxyethyl)pyrrolidine, 1-(2-hydroxyethyl)-2-pyrrolidinone,3-piperidino-1,2-propanediol, 3-pyrrolidino-1,2-propanediol,8-hydroxyjulolidine, 3-quinuclidinol, 3-tropanol, 1-methyl-2-pyrrolidineethanol, 1-aziridine ethanol, N-(2-hydroxyethyl)phthalimide, andN-(2-hydroxyethyl)isonicotinamide. Examples of suitable amidederivatives include formamide, N-methylformamide, N,N-dimethylformamide,acetamide, N-methylacetamide, N,N-dimethylacetamide, propionamide, andbenzamide. Suitable imide derivatives include phthalimide, succinimide,and maleimide.

In addition, basic compounds of the following general formula (D1) mayalso be included alone or in admixture.

N(X′)_(W)(Y)_(3-W)   D1

In the formula, w is equal to 1, 2 or 3; Y is independently hydrogen ora straight, branched or cyclic alkyl group of 1 to 20 carbon atoms whichmay contain a hydroxyl group or ether structure; and X′ is independentlyselected from groups of the following general formulas (X′1) to (X′3),and two or three X′ may bond together to form a ring.

In the formulas, R³⁰⁰, R³⁰² and R³⁰⁵ are independently straight orbranched alkylene groups of 1 to 4 carbon atoms; R³⁰¹, R³⁰⁴ and R³⁰⁶ areindependently hydrogen, straight, branched or cyclic alkyl groups of 1to 20 carbon atoms, which may contain at least one hydroxyl group, etherstructure, ester structure or lactone ring; and R³⁰³ is a single bond ora straight or branched alkylene group of 1 to 4 carbon atoms.

Illustrative examples of the basic compounds of formula (D1) includetris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine,tris{2-(2-methoxy-ethoxymethoxy)ethyl}amine,tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine,tris{2-(1-ethoxypropoxy)ethyl}amine,tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine,4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane,4,7,13,18-tetraoxa-1,10-diazabicyclo[8.5.5]eicosane,1,4,10,13-tetraoxa-7,16-diazabicyclo-octadecane, 1-aza-12-crown-4,1-aza-15-crown-5, 1-aza-18-crown-6, tris(2-formyloxyethyl)amine,tris(2-acetoxyethyl)amine, tris(2-propionyloxyethyl)amine,tris(2-butyryloxyethyl)amine, tris(2-isobutyryloxyethyl)amine,tris(2-valeryloxyethyl)amine, tris(2-pivaloyloxyethyl)amine,N,N-bis(2-acetoxyethyl)-2-(acetoxyacetoxy)ethylamine,tris(2-methoxycarbonyloxyethyl)amine,tris(2-tert-butoxycarbonyloxyethyl)amine,tris[2-(2-oxopropoxy)ethyl]amine,tris[2-(methoxycarbonylmethyl)oxyethyl]amine,tris[2-(tert-butoxycarbonylmethyloxy)ethyl]amine,tris[2-(cyclohexyloxycarbonylmethyloxy)ethyl]amine,tris(2-methoxycarbonylethyl)amine, tris(2-ethoxycarbonylethyl)amine,N,N-bis(2-hydroxyethyl)-2-(methoxycarbonyl)ethylamine,N,N-bis(2-acetoxyethyl)-2-(methoxycarbonyl)ethylamine,N,N-bis(2-hydroxy-ethyl)-2-(ethoxycarbonyl)ethylamine,N,N-bis(2-acetoxy-ethyl)-2-(ethoxycarbonyl)ethylamine,N,N-bis(2-hydroxy-ethyl)-2-(2-methoxyethoxycarbonyl)ethylamine,N,N-bis(2-acetoxyethyl)-2-(2-methoxyethoxycarbonyl)ethylamine,N,N-bis(2-hydroxyethyl)-2-(2-hydroxyethoxycarbonyl)ethylamine,N,N-bis(2-acetoxyethyl)-2-(2-acetoxyethoxycarbonyl)ethylamine,N,N-bis(2-hydroxyethyl)-2-[(methoxycarbonyl)methoxycarbonyl]ethylamine,N,N-bis(2-acetoxyethyl)-2-[(methoxycarbonyl)methoxycarbonyl]ethylamine,N,N-bis(2-hydroxyethyl)-2-(2-oxopropoxycarbonyl)ethylamine,N,N-bis(2-acetoxyethyl)-2-(2-oxopropoxycarbonyl)ethylamine,N,N-bis(2-hydroxyethyl)-2-(tetrahydrofurfuryloxycarbonyl)ethylamine,N,N-bis(2-acetoxyethyl)-2-(tetrahydrofurfuryloxycarbonyl)ethylamine,N,N-bis(2-hydroxyethyl)-2-[(2-oxotetrahydrofuran-3-yl)oxycarbonyl]ethylamine,N,N-bis(2-acetoxyethyl)-2-[(2-oxotetrahydrofuran-3-yl)oxycarbonyl]ethylamine,N,N-bis(2-hydroxyethyl)-2-(4-hydroxybutoxycarbonyl)ethylamine,N,N-bis(2-formyloxyethyl)-2-(4-formyloxybutoxycarbonyl)ethylamine,N,N-bis(2-formyloxyethyl)-2-(2-formyloxyethoxycarbonyl)ethylamine,N,N-bis(2-methoxyethyl)-2-(methoxycarbonyl)ethylamine,N-(2-hydroxyethyl)-bis[2-(methoxycarbonyl)ethyl]amine,N-(2-acetoxyethyl)-bis[2-(methoxycarbonyl)ethyl]amine,N-(2-hydroxyethyl)-bis[2-(ethoxycarbonyl)ethyl]amine,N-(2-acetoxyethyl)-bis[2-(ethoxycarbonyl)ethyl]amine,N-(3-hydroxy-1-propyl)-bis[2-(methoxycarbonyl)ethyl]amine,N-(3-acetoxy-1-propyl)-bis[2-(methoxycarbonyl)ethyl]amine,N-(2-methoxyethyl)-bis[2-(methoxycarbonyl)ethyl]amine,N-butyl-bis[2-(methoxycarbonyl)ethyl]amine,N-butyl-bis[2-(2-methoxyethoxycarbonyl)ethyl]amine,N-methyl-bis(2-acetoxyethyl)amine, N-ethyl-bis(2-acetoxyethyl)amine,N-methyl-bis(2-pivaloyloxyethyl)amine,N-ethyl-bis[2-(methoxycarbonyloxy)ethyl]amine,N-ethyl-bis[2-(tert-butoxycarbonyloxy)ethyl]amine,tris(methoxycarbonylmethyl)amine, tris(ethoxycarbonylmethyl)amine,N-butyl-bis(methoxycarbonylmethyl)amine,N-hexyl-bis(methoxycarbonylmethyl)amine, andβ-(diethylamino)-δ-valerolactone.

Also useful are one or more of cyclic structure-bearing basic compoundshaving the following general formula (D2).

Herein X′ is as defined above, and R³⁰⁷ is a straight or branchedalkylene group of 2 to 20 carbon atoms which may contain one or morecarbonyl groups, ether structures, ester structures or sulfidestructures.

Illustrative examples of the cyclic structure-bearing basic compoundshaving formula (D2) include 1-[2-(methoxymethoxy)ethyl]pyrrolidine,1-[2-(methoxymethoxy)ethyl]piperidine,4-[2-(methoxymethoxy)ethyl]morpholine,1-[2-[(2-methoxyethoxy)methoxy]ethyl]pyrrolidine,1-[2-[(2-methoxyethoxy)methoxy]ethyl]piperidine,4-[2-[(2-methoxyethoxy)methoxy]ethyl]morpholine, 2-(1-pyrrolidinyl)ethylacetate, 2-piperidinoethyl acetate, 2-morpholinoethyl acetate,2-(1-pyrrolidinyl)ethyl formate, 2-piperidinoethyl propionate,2-morpholinoethyl acetoxyacetate, 2-(1-pyrrolidinyl)ethylmethoxyacetate, 4-[2-(methoxycarbonyloxy)ethyl]morpholine,1-[2-(t-butoxycarbonyloxy)ethyl]piperidine,4-[2-(2-methoxyethoxycarbonyloxy)ethyl]morpholine, methyl3-(1-pyrrolidinyl)propionate, methyl 3-piperidinopropionate, methyl3-morpholinopropionate, methyl 3-(thiomorpholino)propionate, methyl2-methyl-3-(1-pyrrolidinyl)propionate, ethyl 3-morpholinopropionate,methoxycarbonylmethyl 3-piperidinopropionate, 2-hydroxyethyl3-(1-pyrrolidinyl)propionate, 2-acetoxyethyl 3-morpholinopropionate,2-oxotetrahydrofuran-3-yl 3-(1-pyrrolidinyl)propionate,tetrahydrofurfuryl 3-morpholinopropionate, glycidyl3-piperidinopropionate, 2-methoxyethyl 3-morpholinopropionate,2-(2-methoxyethoxy)ethyl 3-(1-pyrrolidinyl)propionate, butyl3-morpholinopropionate, cyclohexyl 3-piperidinopropionate,α-(1-pyrrolidinyl)methyl-γ-butyrolactone, β-piperidino-γ-butyrolactone,β-morpholino-δ-valerolactone, methyl 1-pyrrolidinylacetate, methylpiperidinoacetate, methyl morpholinoacetate, methylthiomorpholinoacetate, ethyl 1-pyrrolidinylacetate, and 2-methoxyethylmorpholinoacetate.

Also, one or more of cyano-bearing basic compounds having the followinggeneral formulae (D3) to (D6) may be blended.

Herein, X′, R³⁰⁷ and w are as defined above, and R³⁰⁸ and R³⁰⁹ each areindependently a straight or branched alkylene group of 1 to 4 carbonatoms.

Illustrative examples of the cyano-bearing basic compounds havingformulae (D3) to (D6) include 3-(diethylamino)propiononitrile,N,N-bis(2-hydroxyethyl)-3-aminopropiononitrile,N,N-bis(2-acetoxyethyl)-3-aminopropiononitrile,N,N-bis(2-formyloxyethyl)-3-aminopropiononitrile,N,N-bis(2-methoxyethyl)-3-aminopropiononitrile,N,N-bis[2-(methoxymethoxy)ethyl]-3-aminopropiononitrile, methylN-(2-cyanoethyl)-N-(2-methoxyethyl)-3-aminopropionate, methylN-(2-cyanoethyl)-N-(2-hydroxyethyl)-3-aminopropionate, methylN-(2-acetoxyethyl)-N-(2-cyanoethyl)-3-aminopropionate,N-(2-cyanoethyl)-N-ethyl-3-aminopropiononitrile,N-(2-cyanoethyl)-N-(2-hydroxyethyl)-3-aminopropiononitrile,N-(2-acetoxyethyl)-N-(2-cyanoethyl)-3-aminopropiononitrile,N-(2-cyanoethyl)-N-(2-formyloxyethyl)-3-aminopropiononitrile,N-(2-cyanoethyl)-N-(2-methoxyethyl)-3-aminopropiononitrile,N-(2-cyanoethyl)-N-[2-(methoxymethoxy)ethyl]-3-aminopropiononitrile,N-(2-cyanoethyl)-N-(3-hydroxy-1-propyl)-3-aminopropiononitrile,N-(3-acetoxy-1-propyl)-N-(2-cyanoethyl)-3-aminopropiononitrile,N-(2-cyanoethyl)-N-(3-formyloxy-1-propyl)-3-aminopropiononitrile,N-(2-cyanoethyl)-N-tetrahydrofurfuryl-3-aminopropiononitrile,N,N-bis(2-cyanoethyl)-3-aminopropiononitrile, diethylaminoacetonitrile,N,N-bis(2-hydroxyethyl)aminoacetonitrile,N,N-bis(2-acetoxyethyl)aminoacetonitrile,N,N-bis(2-formyloxyethyl)aminoacetonitrile,N,N-bis(2-methoxyethyl)aminoacetonitrile,N,N-bis[2-(methoxymethoxy)ethyl]aminoacetonitrile, methylN-cyanomethyl-N-(methoxyethyl)-3-aminopropionate, methylN-cyanomethyl-N-(2-hydroxyethyl)-3-aminopropionate, methylN-(2-acetoxyethyl)-N-cyanomethyl-3-aminopropionate,N-cyanomethyl-N-(2-hydroxyethyl)aminoacetonitrile,N-(2-acetoxyethyl)-N-(cyanomethyl)aminoacetonitrile,N-cyanomethyl-N-(2-formyloxyethyl)aminoacetonitrile,N-cyanomethyl-N-(2-methoxyethyl)aminoacetonitrile,N-cyanomethyl-N-[2-(methoxymethoxy)ethyl)aminoacetonitrile,N-cyanomethyl-N-(3-hydroxy-1-propyl)aminoacetonitrile,N-(3-acetoxy-1-propyl)-N-(cyanomethyl)aminoacetonitrile,N-cyanomethyl-N-(3-formyloxy-1-propyl)aminoacetonitrile,N,N-bis(cyanomethyl)aminoacetonitrile, 1-pyrrolidinepropiononitrile,1-piperidinepropiononitrile, 4-morpholinepropiononitrile,1-pyrrolidineacetonitrile, 1-piperidineacetonitrile,4-morpholineacetonitrile, cyanomethyl 3-diethylaminopropionate,cyanomethyl N,N-bis(2-hydroxyethyl)-3-aminopropionate, cyanomethylN,N-bis(2-acetoxyethyl)-3-aminopropionate, cyanomethylN,N-bis(2-formyloxyethyl)-3-aminopropionate, cyanomethylN,N-bis(2-methoxyethyl)-3-aminopropionate, cyanomethylN,N-bis[2-(methoxymethoxy)ethyl]-3-aminopropionate, 2-cyanoethyl3-diethylaminopropionate, 2-cyanoethylN,N-bis(2-hydroxyethyl)-3-aminopropionate, 2-cyanoethylN,N-bis(2-acetoxyethyl)-3-aminopropionate, 2-cyanoethylN,N-bis(2-formyloxyethyl)-3-aminopropionate, 2-cyanoethylN,N-bis(2-methoxyethyl)-3-aminopropionate, 2-cyanoethylN,N-bis[2-(methoxymethoxy)ethyl]-3-aminopropionate, cyanomethyl1-pyrrolidinepropionate, cyanomethyl 1-piperidinepropionate, cyanomethyl4-morpholinepropionate, 2-cyanoethyl 1-pyrrolidinepropionate,2-cyanoethyl 1-piperidinepropionate, and 2-cyanoethyl4-morpholinepropionate.

The basic compounds may be used alone or in admixture of two or more.The basic compound is preferably formulated in an amount of 0 to 2parts, and especially 0.01 to 1 part by weight, per 100 parts by weightof the solids in the resist composition. The use of more than 2 parts ofthe basis compound would result in too low a sensitivity.

Component (E)

Illustrative, non-limiting, examples of the organic acid derivatives (E)include phenol, cresol, catechol, resorcinol, pyrogallol, fluoroglycin,bis(4-hydroxyphenyl)methane, 2,2-bis(4′-hydroxyphenyl)propane,bis(4-hydroxyphenyl)sulfone, 1,1,1-tris(4′-hydroxyphenyl)ethane,1,1,2-tris(4′-hydroxyphenyl)ethane, hydroxybenzophenone,4-hydroxyphenylacetic acid, 3-hydroxyphenylacetic acid,2-hydroxyphenylacetic acid, 3-(4-hydroxyphenyl)propionic acid,3-(2-hydroxyphenyl)propionic acid, 2,5-dihydroxyphenylacetic acid,3,4-dihydroxyphenylacetic acid, 1,2-phenylenediacetic acid,1,3-phenylenediacetic acid, 1,4-phenylenediacetic acid,1,2-phenylenedioxydiacetic acid, 1,4-phenylenedipropanoic acid, benzoicacid, salicylic acid, 4,4-bis(4′-hydroxyphenyl)valeric acid,4-tert-butoxyphenylacetic acid, 4-(4-hydroxyphenyl)butyric acid,3,4-dihydroxymandelic acid, and 4-hydroxymandelic acid. Of these,salicylic acid and 4,4-bis(4′-hydroxyphenyl)valeric acid are preferred.They may be used alone or in admixture of two or more.

In the resist composition comprising the sulfonyldiazomethane as thephotoacid generator according to the invention, the organic acidderivative is preferably formulated in an amount of up to 5 parts, andespecially up to 1 part by weight, per 100 parts by weight of the solidsin the resist composition. The use of more than 5 parts of the organicacid derivative would result in too low a resolution. Depending on thecombination of the other components in the resist composition, theorganic acid derivative may be omitted.

Component (F)

Component (F) is an organic solvent. Illustrative, non-limiting,examples include butyl acetate, amyl acetate, cyclohexyl acetate,3-methoxybutyl acetate, methyl ethyl ketone, methyl amyl ketone,cyclohexanone, cyclopentanone, 3-ethoxyethyl propionate, 3-ethoxymethylpropionate, 3-methoxymethyl propionate, methyl acetoacetate, ethylacetoacetate, diacetone-alcohol, methyl pyruvate, ethyl pyruvate,propylene glycol monomethyl ether, propylene glycol monoethyl ether,propylene glycol monomethyl ether propionate, propylene glycol monoethylether propionate, ethylene glycol monomethyl ether, ethylene glycolmonoethyl ether, diethylene glycol monomethyl ether, diethylene glycolmonoethyl ether, 3-methyl-3-methoxybutanol, N-methyl-pyrrolidone,dimethyl sulfoxide, γ-butyrolactone, propylene glycol methyl etheracetate, propylene glycol ethyl ether acetate, propylene glycol propylether acetate, methyl lactate, ethyl lactate, propyl lactate, andtetramethyl sulfone. Of these, the propylene glycol alkyl ether acetatesand alkyl lactates are especially preferred. The solvents may be usedalone or in admixture of two or more. An exemplary useful solventmixture is a mixture of a propylene glycol alkyl ether acetate and analkyl lactate. It is noted that the alkyl groups of the propylene glycolalkyl ether acetates are preferably those of 1 to 4 carbon atoms, forexample, methyl, ethyl and propyl, with methyl and ethyl beingespecially preferred. Since the propylene glycol alkyl ether acetatesinclude 1,2- and 1,3-substituted ones, each includes three isomersdepending on the combination of substituted positions, which may be usedalone or in admixture.

When the propylene glycol alkyl ether acetate is used as the solvent, itpreferably accounts for at least 50% by weight of the entire solvent.Also when the alkyl lactate is used as the solvent, it preferablyaccounts for at least 50% by weight of the entire solvent. When amixture of propylene glycol alkyl ether acetate and alkyl lactate isused as the solvent, that mixture preferably accounts for at least 50%by weight of the entire solvent. In this solvent mixture, it is furtherpreferred that the propylene glycol alkyl ether acetate is 60 to 95% byweight and the alkyl lactate is 40 to 5% by weight. A lower proportionof the propylene glycol alkyl ether acetate would invite a problem ofinefficient coating whereas a higher proportion thereof would provideinsufficient dissolution and allow for particle and foreign matterformation. A lower proportion of the alkyl lactate would provideinsufficient dissolution and cause the problem of many particles andforeign matter whereas a higher proportion thereof would lead to acomposition which has a too high viscosity to apply and loses storagestability.

The solvent is preferably used in an amount of 300 to 2,000 parts byweight, especially 400 to 1,000 parts by weight per 100 parts by weightof the solids in the resist composition. The solvent concentration isnot limited thereto as long as a film can be formed by existing methods.

Component (G)

In one preferred embodiment, the resist composition further contains (G)a compound with a molecular weight of up to 3,000 which changes itssolubility in an alkaline developer under the action of an acid, thatis, a dissolution inhibitor. Typically, a compound obtained by partiallyor entirely substituting acid labile substituents on a phenol orcarboxylic acid derivative having a molecular weight of up to 2,500 isadded as the dissolution inhibitor.

Examples of the phenol or carboxylic acid derivative having a molecularweight of up to 2,500 include bisphenol A, bisphenol H, bisphenol S,4,4-bis(4′-hydroxyphenyl)valeric acid, tris(4-hydroxyphenyl)methane,1,1,1-tris(4′-hydroxyphenyl)ethane, 1,1,2-tris(4′-hydroxyphenyl)ethane,phenolphthalein, and thymolphthalein. The acid labile substituents arethe same as those exemplified as the acid labile groups in the polymer.

Illustrative, non-limiting, examples of the dissolution inhibitors whichare useful herein include bis(4-(2′-tetrahydropyranyloxy)phenyl)methane,bis(4-(2′-tetrahydrofuranyloxy)phenyl)methane,bis(4-tert-butoxyphenyl)methane,bis(4-tert-butoxycarbonyloxyphenyl)methane,bis(4-tert-butoxycarbonylmethyloxyphenyl)methane,bis(4-(1′-ethoxyethoxy)phenyl)methane,bis(4-(1′-ethoxypropyloxy)phenyl)methane,2,2-bis(4′-(2″-tetrahydropyranyloxy))propane,2,2-bis(4′-(2″-tetrahydrofuranyloxy)phenyl)propane,2,2-bis(4′-tert-butoxyphenyl)propane,2,2-bis(4′-tert-butoxycarbonyloxyphenyl)propane,2,2-bis(4-tert-butoxycarbonylmethyloxyphenyl)propane,2,2-bis(4′-(1″-ethoxyethoxy)phenyl)propane,2,2-bis(4′-(1″-ethoxypropyloxy)phenyl)propane, tert-butyl4,4-bis(4′-(2″-tetrahydropyranyloxy)phenyl)valerate, tert-butyl4,4-bis(4′-(2″-tetrahydrofuranyloxy)phenyl)valerate, tert-butyl4,4-bis(4′-tert-butoxyphenyl)valerate, tert-butyl4,4-bis(4-tert-butoxycarbonyloxyphenyl)valerate, tert-butyl4,4-bis(4′-tert-butoxycarbonylmethyloxyphenyl)valerate, tert-butyl4,4-bis(4′-(1″-ethoxyethoxy)phenyl)valerate, tert-butyl4,4-bis(4′-(1″-ethoxypropyloxy)phenyl)valerate,tris(4-(2′-tetrahydropyranyloxy)phenyl)methane,tris(4-(2′-tetrahydrofuranyloxy)phenyl)methane,tris(4-tert-butoxyphenyl)methane,tris(4-tert-butoxycarbonyloxyphenyl)methane,tris(4-tert-butoxycarbonyloxymethylphenyl)methane,tris(4-(1′-ethoxyethoxy)phenyl)methane,tris(4-(1′-ethoxypropyloxy)phenyl)methane,1,1,2-tris(4′-(2″-tetrahydropyranyloxy)phenyl)ethane,1,1,2-tris(4′-(2″-tetrahydrofuranyloxy)phenyl)ethane,1,1,2-tris(4′-tert-butoxyphenyl)ethane,1,1,2-tris(4′-tert-butoxycarbonyloxyphenyl)ethane,1,1,2-tris(4′-tert-butoxycarbonylmethyloxyphenyl)ethane,1,1,2-tris(4′-(1′-ethoxyethoxy)phenyl)ethane, and1,1,2-tris(4′-(1′-ethoxypropyloxy)phenyl)ethane.

In the resist composition comprising the sulfonyldiazomethane of formula(1) or (1a) as the photoacid generator according to the invention, anappropriate amount of the dissolution inhibitor is up to 20 parts, andespecially up to 15 parts by weight per 100 parts by weight of thesolids in the resist composition. With more than 20 parts of thedissolution inhibitor, the resist composition becomes less heatresistant because of an increased content of monomer components.

Component (H)

In a chemical amplification, negative working, resist composition aswell, the sulfonyldiazomethane of formula (1) or (1a) according to theinvention may be used as the photoacid generator. This compositionfurther contains an alkali-soluble resin as component (H), examples ofwhich are intermediates of the above-described component (A) though notlimited thereto. Examples of the alkali-soluble resin includepoly(p-hydroxystyrene), poly(m-hydroxystyrene),poly(4-hydroxy-2-methylstyrene), poly(4-hydroxy-3-methylstyrene),poly(α-methyl-p-hydroxystyrene), partially hydrogenated p-hydroxystyrenecopolymers, p-hydroxystyrene-α-methyl-p-hydroxystyrene copolymers,p-hydroxystyrene-α-methylstyrene copolymers, p-hydroxystyrene-styrenecopolymers, p-hydroxystyrene-m-hydroxystyrene copolymers,p-hydroxystyrene-styrene copolymers, p-hydroxystyrene-acrylic acidcopolymers, p-hydroxystyrene-methacrylic acid copolymers,p-hydroxystyrene-methyl methacrylate copolymers,p-hydroxystyrene-acrylic acid-methyl methacrylate copolymers,p-hydroxystyrene-methyl acrylate copolymers,p-hydroxystyrene-methacrylic acid-methyl methacrylate copolymers,poly(methacrylic acid), poly(acrylic acid), acrylic acid-methyl acrylatecopolymers, methacrylic acid-methyl methacrylate copolymers, acrylicacid-maleimide copolymers, methacrylic acid-maleimide copolymers,p-hydroxystyrene-acrylic acid-maleimide copolymers, andp-hydroxystyrene-methacrylic acid-maleimide copolymers, but are notlimited to these combinations.

Preferred are poly(p-hydroxystyrene), partially hydrogenatedp-hydroxystyrene copolymers, p-hydroxystyrene-styrene copolymers,p-hydroxystyrene-acrylic acid copolymers, andp-hydroxystyrene-methacrylic acid copolymers.

Alkali-soluble resins comprising units of the following formula (2),(2′), (2″) or (2″′) are especially preferred.

Herein R⁴ is hydrogen or methyl; and R⁵ is a straight, branched orcyclic alkyl group of 1 to 8 carbon atoms. The subscript x is 0 or apositive integer; y is a positive integer, satisfying x+y≦5, yy is 0 ora positive integer, satisfying x+yy≦5; M and N are positive integers,satisfying 0<N/(M+N)≦0.5; A and B are positive integers, C is 0 or apositive integer, satisfying 0<B/(A+B+C)≦0.5, ZZ is a divalent groupselected from among CH₂, CH(OH), CR⁵(OH), C═O and C(OR⁵)(OH), or atrivalent organic group represented by —C(OH)═; F is independently apositive integer, and H is a positive integer, satisfying0.001≦H/(H+F)≦0.1; and XX is 1 or 2.

The polymer should preferably have a weight average molecular weight(Mw) of 3,000 to 100,000. Many polymers with Mw of less than 3,000 donot perform well and are poor in heat resistance and film formation.Many polymers with Mw of more than 100,000 give rise to a problem withrespect to dissolution in the resist solvent and developer. The polymershould also preferably have a dispersity (Mw/Mn) of up to 3.5, and morepreferably up to 1.5. With a dispersity of more than 3.5, resolution islow in many cases. Although the preparation method is not critical, apoly(p-hydroxystyrene) or similar polymer with a low dispersity ornarrow dispersion can be synthesized by living anion polymerization.

To impart a certain function, suitable substituent groups may beintroduced into some of the phenolic hydroxyl and carboxyl groups on theforegoing polymer. Exemplary and preferred are substituent groups forimproving adhesion to the substrate, substituent groups for improvingetching resistance, and especially substituent groups which arerelatively stable against acid and alkali and effective for controllingsuch that the dissolution rate in an alkali developer of unexposed andlow exposed areas of a resist film may not become too high.Illustrative, non-limiting, substituent groups include 2-hydroxyethyl,2-hydroxypropyl, methoxymethyl, methoxycarbonyl, ethoxycarbonyl,methoxycarbonylmethyl, ethoxycarbonylmethyl, 4-methyl-2-oxo-4-oxoranyl,4-methyl-2-oxo-4-oxanyl, methyl, ethyl, n-propyl, isopropyl, n-butyl,sec-butyl, acetyl, pivaloyl, adamantyl, isoboronyl, and cyclohexyl. Itis also possible to introduce acid-decomposable substituent groups suchas t-butoxycarbonyl and relatively acid-undecomposable substituentgroups such as t-butyl and t-butoxycarbonylmethyl.

In the resist composition, the above resin is blended in any desiredamount, preferably of 65 to 99 parts by weight, especially 70 to 98parts by weight per 100 parts by weight of the solids.

Also contained in the negative resist composition is (I) an acidcrosslinking agent capable of forming a crosslinked structure under theaction of an acid. Typical acid crosslinking agents are compounds havingat least two hydroxymethyl, alkoxymethyl, epoxy or vinyl ether groups ina molecule. Substituted glycoluril derivatives, urea derivatives, andhexa(methoxymethyl)melamine compounds are suitable as the acidcrosslinking agent in the chemically amplified, negative resistcomposition comprising the sulfonyldiazomethane. Examples includeN,N,N′,N′-tetramethoxymethylurea, hexamethoxymethylmelamine,tetraalkoxymethyl-substituted glycoluril compounds such astetrahydroxymethyl-substituted glycoluril andtetramethoxymethylglycoluril, and condensates of phenolic compounds suchas substituted or unsubstituted bis(hydroxymethylphenol) compounds andbisphenol A with epichlorohydrin. Especially preferred acid crosslinkingagents are 1,3,5,7-tetraalkoxymethylglycolurils such as1,3,5,7-tetramethoxymethylglycoluril,1,3,5,7-tetrahydroxymethylglycoluril, 2,6-dihydroxymethyl-p-cresol,2,6-dihydroxymethylphenol, 2,2′,6,6′-tetrahydroxymethyl-bisphenol A,1,4-bis[2-(2-hydroxypropyl)]benzene, N,N,N′,N′-tetramethoxymethylurea,and hexamethoxymethylmelamine.

An appropriate amount of the acid crosslinking agent is, but not limitedthereto, about 1 to 20 parts, and especially about 5 to 15 parts byweight per 100 parts by weight of the solids in the resist composition.The acid crosslinking agents may be used alone or in admixture of any.

Component (J) is an alkali-soluble compound having a molecular weight ofup to 2,500. Any suitable compound may be used although a compoundhaving at least two phenol and/or carboxyl groups is preferred.Illustrative, non-limiting, examples of the alkali-soluble compound (J)include cresol, catechol, resorcinol, pyrogallol, phloroglucinol,bis(4-hydroxyphenyl)methane, 2,2-bis(4′-hydroxyphenyl)propane,bis(4-hydroxyphenyl)sulfone, 1,1,1-tris(4′-hydroxyphenyl)ethane,1,1,2-tris(4′-hydroxyphenyl)ethane, hydroxybenzophenone,4-hydroxyphenylacetic acid, 3-hydroxyphenylacetic acid,2-hydroxyphenylacetic acid, 3-(4-hydroxyphenyl)propionic acid,3-(2-hydroxyphenyl)propionic acid, 2,5-dihydroxyphenylacetic acid,3,4-dihydroxyphenylacetic acid, 1,2-phenylenediacetic acid,1,3-phenylenediacetic acid, 1,4-phenylenediacetic acid,1,2-phenylenedioxydiacetic acid, 1,4-phenylenedipropanoic acid, benzoicacid, salicylic acid, 4,4-bis(4′-hydroxyphenyl)valeric acid,4-tert-butoxyphenylacetic acid, 4-(4-hydroxyphenyl)butyric acid,3,4-dihydroxymandelic acid, and 4-hydroxymandelic acid. Of these,salicylic acid and 4,4-bis(4′-hydroxyphenyl)valeric acid are preferred.They may be used alone or in admixture of two or more. Thealkali-soluble compound is blended in any desired amount, preferably of0 to 20 parts by weight, especially 2 to 10 parts by weight per 100parts by weight of the solids in the resist composition.

In the chemical amplification type resist composition according to theinvention, there may be added such additives as a surfactant forimproving coating, and a light absorbing agent for reducing diffusereflection from the substrate.

Illustrative, non-limiting, examples of the surfactant include nonionicsurfactants, for example, polyoxyethylene alkyl ethers such aspolyoxyethylene lauryl ether, polyoxyethylene stearyl ether,polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether,polyoxyethylene alkylaryl ethers such as polyoxyethylene octylphenolether and polyoxyethylene nonylphenol ether, polyoxyethylenepolyoxypropylene block copolymers, sorbitan fatty acid esters such assorbitan monolaurate, sorbitan monopalmitate, and sorbitan monostearate,and polyoxyethylene sorbitan fatty acid esters such as polyoxyethylenesorbitan monolaurate, polyoxyethylene sorbitan monopalmitate,polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitantrioleate, and polyoxyethylene sorbitan tristearate; fluorochemicalsurfactants such as EFTOP EF301, EF303 and EF352 (Tohkem Products K.K.),Megaface F171, F172 and F173 (Dai-Nippon Ink & Chemicals K.K.), FloradeFC430 and FC431 (Sumitomo 3M K.K.), Aashiguard AG710, Surflon S-381,S-382, SC101, SC102, SC103, SC104, SC105, SC106, Surfynol E1004, KH-10,KH-20, KH-30 and KH-40 (Asahi Glass K.K.); organosiloxane polymersKP341, X-70-092 and X-70-093 (Shin-Etsu Chemical Co., Ltd.), acrylicacid or methacrylic acid Polyflow No. 75 and No. 95 (Kyoeisha UshiKagaku Kogyo K.K.). Inter alia, FC430, Surflon S-381, Surfynol E1004,KH-20 and KH-30 are preferred. These surfactants may be used alone or inadmixture.

In the chemical amplification type resist composition according to theinvention, the surfactant is preferably formulated in an amount of up to2 parts, and especially up to 1 part by weight, per 100 parts by weightof the solids in the resist composition.

In the chemical amplification type resist composition according to theinvention, a UV absorber may be added. Those UV absorbers described inJP-A 11-190904 are useful, but the invention is not limited thereto.

Exemplary UV absorbers are diaryl sulfoxide derivatives such asbis(4-hydroxyphenyl) sulfoxide, bis(4-tert-butoxyphenyl) sulfoxide,bis(4-tert-butoxycarbonyloxyphenyl) sulfoxide, andbis[4-(1-ethoxyethoxy)phenyl]sulfoxide; diarylsulfone derivatives suchas bis(4-hydroxyphenyl)sulfone, bis(4-tert-butoxyphenyl)sulfone,bis(4-tert-butoxycarbonyloxyphenyl)sulfone,bis[4-(1-ethoxyethoxy)-phenyl]sulfone, andbis[4-(1-ethoxypropoxy)phenyl]sulfone; diazo compounds such asbenzoquinonediazide, naphthoquinonediazide, anthraquinonediazide,diazofluorene, diazotetralone, and diazophenanthrone; quinonediazidegroup-containing compounds such as complete or partial ester compoundsbetween naphthoquinone-1,2-diazide-5-sulfonic acid chloride and2,3,4-trihydroxybenzophenone and complete or partial ester compoundsbetween naphthoquinone-1,2-diazide-4-sulfonic acid chloride and2,4,4′-trihydroxybenzophenone; tert-butyl 9-anthracenecarboxylate,tert-amyl 9-anthracenecarboxylate, tert-methoxymethyl9-anthracenecarboxylate, tert-ethoxyethyl 9-anthracenecarboxylate,2-tert-tetrahydropyranyl 9-anthracenecarboxylate, and2-tert-tetrahydrofuranyl 9-anthracenecarboxylate. The UV absorber may ormay not be added to the resist composition depending on the type ofresist composition. An appropriate amount of UV absorber, if added, is 0to 10 parts, more preferably 0.5 to 10 parts, most preferably 1 to 5parts by weight per 100 parts by weight of the base resin.

For the microfabrication of integrated circuits, any well-knownlithography may be used to form a resist pattern from the chemicalamplification type resist composition comprising thesulfonyldiazomethane photoacid generator of formula (1) or (1a) and theresin which changes solubility in an alkaline developer under the actionof acid according to the invention.

The composition is applied onto a substrate (e.g., Si, SiO₂, SiN, SiON,TiN, WSi, BPSG, SOG, organic anti-reflecting film, etc.) by a suitablecoating technique such as spin coating, roll coating, flow coating, dipcoating, spray coating or doctor coating. The coating is prebaked on ahot plate at a temperature of 60 to 150° C. for about 1 to 10 minutes,preferably 80 to 120° C. for 1 to 5 minutes. The resulting resist filmis generally 0.1 to 2.0 μm thick. With a mask having a desired patternplaced above the resist film, the resist film is then exposed to actinicradiation, preferably having an exposure wavelength of up to 300 nm,such as UV, deep-UV, electron beams, x-rays, excimer laser light, γ-raysand synchrotron radiation in an exposure dose of about 1 to 200 mJ/cm²,preferably about 10 to 100 mJ/cm². The film is further baked on a hotplate at 60 to 150° C. for 1 to 5 minutes, preferably 80 to 120° C. for1 to 3 minutes (post-exposure baking=PEB).

Thereafter the resist film is developed with a developer in the form ofan aqueous base solution, for example, 0.1 to 5%, preferably 2 to 3%aqueous solution of tetramethylammonium hydroxide (TMAH) for 0.1 to 3minutes, preferably 0.5 to 2 minutes by conventional techniques such asdipping, puddling or spraying. In this way, a desired resist pattern isformed on the substrate. It is appreciated that the resist compositionof the invention is best suited for micro-patterning using such actinicradiation as deep UV with a wavelength of 254 to 193 nm, vacuum UV witha wavelength of 157 nm, electron beams, x-rays, excimer laser light,γ-rays and synchrotron radiation. With any of the above-describedparameters outside the above-described range, the process may sometimesfail to produce the desired pattern.

EXAMPLE

Examples of the invention are given below by way of illustration and notby way of limitation.

Synthesis Example 1

Synthesis of 4-n-butoxythiophenol

In 200 g of ethanol were dissolved 86.5 g (0.5 mol) of 4-bromophenol and22 g (0.55 mol) of sodium hydroxide. To the solution at 70° C., 75.4 g(0.55 mol) of n-butyl bromide was added dropwise. The solution wasallowed to ripen for 4 hours and cooled to room temperature, after which120 g of water was added. The oily matter was separated therefrom andconcentrated by a rotary evaporator, yielding 90 g of 4-n-butoxyphenylbromide. This was used in the subsequent reaction without furtherpurification.

Using 9.5 g (0.39 mol) of metallic magnesium, 300 g of tetrahydrofuran,and 90 g (0.39 mol) of the above 4-n-butoxyphenyl bromide, a Grignardreagent was prepared in a conventional manner. The Grignard reagent wasice cooled, to which 12.6 g (0.39 mol) of colloidal sulfur was added ata temperature below 20° C. The solution was ripened for 2 hours at roomtemperature, then ice cooled again. To the solution, 60 g of conc.hydrochloric acid (12N) and 200 g of water were added. The organic layerthus separated was concentrated, obtaining 74 g (yield 82%) of the endcompound, 4-n-butoxythiophenol.

Synthesis Example 2

Synthesis of formaldehyde bis(4-n-butoxyphenylthio)acetal

In 180 g of ethanol were dissolved 45 g (0.25 mol) of the above4-n-butoxythiophenol and 10.3 g (0.26 mol) of sodium hydroxide. To thesolution, 15.9 g (0.19 mol) of dichloromethane was added dropwise at atemperature below 50° C. The solution was heated at 60° C. in an oilbath and ripened for 3 hours at the temperature. It was allowed to coolto room temperature, after which 300 g of water and 200 g ofdichloromethane were added. The organic layer was separated and thesolvent was removed therefrom by a rotary evaporator, collecting 46.1 g(yield 98%) of the end compound, formaldehydebis(4-n-butoxyphenylthio)acetal.

Synthesis Example 3

Synthesis of bis(4-n-butoxyphenylsulfonyl)methane

To 190 g of ethanol were added 46.1 g (0.122 mol) of the formaldehydebis(4-n-butoxyphenylthio)acetal in Synthesis Example 2 and 1.0 g (0.003mol) of sodium tungstate. The solution was heated at 65° C. in an oilbath, to which 67 g (0.69 mol) of aqueous hydrogen peroxide was addeddropwise at a temperature below 70° C. The solution was kept at thetemperature for 4 hours and then cooled in an ice bath whereupon whitecrystals precipitated. The crystals were filtered out, collecting 43.2 g(yield 80%) of the end compound, bis(4-n-butoxyphenylsulfonyl)methane.

Synthesis Example 4

Synthesis of bis(4-n-butoxyphenylsulfonyl)diazomethane

In 200 g of dichloromethane were dissolved 22 g (0.05 mol) of thebis(4-n-butoxyphenylsulfonyl)methane in Synthesis Example 3 and 14.8 g(0.075 mol) of p-toluene-sulfonylazide. The solution was cooled in anice bath, 7.6 g (0.05 mol) of diazabicycloundecene (DBU) was added at atemperature below 5° C. The solution was ripened at the temperature for15 minutes, after which 100 g of water and 15 g of conc. hydrochloricacid (12N) were added. The organic layer was separated and washed with100 g of water, after which the solvent was removed by a rotaryevaporator, obtaining 37 g of an oily matter. It was purified by silicagel column chromatography (eluent: dichloromethane), obtaining 15 g(yield 64%) of the end compound,bis(4-n-butoxyphenylsulfonyl)diazomethane.

The thus obtained bis(4-n-butoxyphenylsulfonyl)diazomethane was analyzedby nuclear magnetic resonance (NMR) spectroscopy and infrared (IR)absorption spectroscopy, with the results shown below.

¹H-NMR: CDCl₃ (ppm) (1) Ha 0.964-1.013 triplet 6H (2) Hb 1.442-1.571multiplet 4H (3) Hc 1.754-1.847 multiplet 4H (4) Hd 4.021-4.064 triplet4H (5) He 6.970-7.000 doublet 4H (6) Hf 7.879-7.909 doublet 4H IR: cm⁻¹2954, 2953, 2117, 2100, 1593, 1497, 1470, 1344, 1309, 1263, 1225, 1207,1180, 1153, 1082, 1024, 981, 839, 806, 719, 688, 632, 582

Synthesis Example 5

Synthesis of 4-n-hexyloxythiophenol

In 200 g of ethanol were dissolved 86.5 g (0.5 mol) of 4-bromophenol and22 g (0.55 mol) of sodium hydroxide. To the solution at 70° C., 90.8 g(0.55 mol) of n-hexyl bromide was added dropwise. The solution wasallowed to ripen for 4 hours and cooled to room temperature, after which120 g of water was added. The oily matter was separated therefrom andconcentrated by a rotary evaporator, followed by vacuum distillation(boiling point 125-128° C./0.5 Torr), yielding 100 g of4-n-hexyloxyphenyl bromide.

Using 9.0 g (0.39 mol) of metallic magnesium, 300 g of tetrahydrofuran,and 100 g (0.39 mol) of the above 4-n-hexyloxyphenyl bromide, a Grignardreagent was prepared in a conventional manner. The Grignard reagent wasice cooled, to which 12.6 g (0.39 mol) of colloidal sulfur was added ata temperature below 20° C. The solution was ripened for 2 hours at roomtemperature, then ice cooled again. To the solution, 60 g of conc.hydrochloric acid (12N) and 200 g of water were added. The organic layerthus separated was concentrated, obtaining 83 g of an oily matter.Vacuum distillation (boiling point 120-130° C./0.5 Torr) of the oilymatter yielded 60 g (yield 57%) of the end compound,4-n-hexyloxythiophenol.

Synthesis Example 6

Synthesis of formaldehyde bis(4-n-hexyloxyphenylthio)acetal

In 240 g of ethanol were dissolved 60 g (0.285 mol) of the above4-n-hexyloxythiophenol and 12.0 g (0.30 mol) of sodium hydroxide. To thesolution, 18.1 g (0.214 mol) of dichloromethane was added dropwise at atemperature below 50° C. The solution was heated at 60° C. in an oilbath and ripened for 3 hours at the temperature. It was allowed to coolto room temperature, after which 300 g of water and 200 g ofdachloromethane ere added. The organic layer was separated and thesolvent was removed therefrom by a rotary evaporator, collecting 61.2 g(yield 99%) of the end compound, formaldehydebis(4-n-hexyloxyphenylthio)acetal.

Synthesis Example 7

Synthesis of bis(4-n-hexyloxyphenylsulfonyl)methane

To 240 g of ethanol were added 61.2 g (0.141 mol) of the formaldehydebis(4-n-hexyloxyphenylthio)acetal in Synthesis Example 6 and 1.0 g(0.003 mol) of sodium tungstate. The solution was heated at 65° C. in anoil bath, to which 69 g (0.71 mol) of aqueous hydrogen peroxide wasadded dropwise at a temperature below 70° C. The solution was kept atthe temperature for 4 hours and then cooled in an ice bath whereuponwhite crystals precipitated. The crystals were filtered out, collecting57 g (yield 81%) of the end compound,bis(4-n-hexyloxyphenylsulfonyl)methane.

Synthesis Example 8

Synthesis of bis(4-n-hexyloxyphenylsulfonyl)diazomethane

In 200 g of dichloromethane were dissolved 20 g (0.04 mol) of thebis(4-n-hexyloxyphenylsulfonyl)methane in Synthesis Example 7 and 11.9 g(0.06 mol) of p-toluene-sulfonylazide. The solution was cooled in an icebath, 6.1 g (0.04 mol) of diazabicycloundecene (DBU) was added at atemperature below 5° C. The solution was ripened at the temperature for15 minutes, after which 100 g of water and 10 g of conc. hydrochloricacid (12N) were added. The organic layer was separated and washed with100 g of water, after which the solvent was removed by a rotaryevaporator, obtaining 37 g of an oily matter. It was purified by silicagel column chromatography (eluent: dichloromethane), obtaining 14.8 g(yield 70%) of the end compound,bis(4-n-hexyloxyphenylsulfonyl)diazomethane.

The thus obtained bis(4-n-hexyloxyphenylsulfonyl)diazomethane wasanalyzed by NMR spectroscopy and IR spectroscopy, with the results shownbelow.

¹H-NMR: CDCl₃ (ppm) (1) Ha 0.891-0.938 triplet 6H (2) Hb 1.30-1.50multiplet 12H (3) Hc 1.766-1.859 quintuplet 4H (4) Hd 4.013-4.056triplet 4H (5) He 6.961-6.994 doublet 4H (6) Hf 7.881-7.904 doublet 4HIR: cm⁻¹ 2939, 2873, 2854, 2103, 1593, 1497, 1475, 1350, 1309, 1261,1213, 1180, 1151, 1084, 1022, 983, 831, 721, 690, 628, 580, 569

Synthesis Example 9

Synthesis of 4-n-hexyloxy-2-methylthiophenol

In 200 g of ethanol were dissolved 71.2 g (0.5 mol) of4-chloro-3-methylphenol and 22 g (0.55 mol) of sodium hydroxide. To thesolution at 70° C., 90.8 g (0.55 mol) of n-hexyl bromide was addeddropwise. The solution was allowed to ripen for 4 hours and cooled toroom temperature, after which 120 g of water was added. The oily matterwas separated therefrom and concentrated by a rotary evaporator,followed by vacuum distillation (boiling point 115-117° C./0.3 Torr),yielding 102 g of 4-n-hexyloxy-2-methylphenyl chloride.

Using 10.9 g (0.45 mol) of metallic magnesium, 150 g of tetrahydrofuran,and 102 g (0.45 mol) of the above 4-n-hexyloxy-2-methylphenyl chloride,a Grignard reagent was prepared in a conventional manner. The Grignardreagent was ice cooled, to which 14.3 g (0.45 mol) of colloidal sulfurwas added at a temperature below 20° C. The solution was ripened for 2hours at room temperature, then ice cooled again. To the solution 60 gof conc. hydrochloric acid (12N) and 200 g of water were added. Theorganic layer thus separated was concentrated, obtaining 83 g of an oilymatter. Vacuum distillation (boiling point 110-190° C./0.3 Torr) of theoily matter yielded 47 g (yield 42%) of the end compound,4-n-hexyloxy-2-methylthiophenol.

Synthesis Example 10

Synthesis of formaldehyde bis(4-n-hexyloxy-2-methylphenylthio)acetal

In 200 g of ethanol were dissolved 47 g (0.21 mol) of the above4-n-hexyloxy-2-methylthiophenol and 8.8 g (0.22 mol) of sodiumhydroxide. To the solution, 13.6 g (0.16 mol) of dichloromethane wasadded dropwise at a temperature below 50° C. The solution was heated at60° C. in an oil bath and ripened for 3 hours at the temperature. It wasallowed to cool to room temperature, after which 200 g of water and 150g of dichloromethane were added. The organic layer was separated and thesolvent was removed therefrom by a rotary evaporator, collecting 46.9 g(yield 97%) of the end compound, formaldehydebis(4-n-hexyloxy-2-methylphenylthio)acetal.

Synthesis Example 11

Synthesis of bis(4-n-hexyloxy-2-methylphenylsulfonyl)methane

To 200 g of ethanol were added 46.9 g (0.102 mol) of the formaldehydebis(4-n-hexyloxy-2-methylphenylthio)acetal in Synthesis Example 10 and1.0 g (0.003 mol) of sodium tungstate. The solution was heated at 65° C.in an oil bath, to which 53 g (0.55 mol) of aqueous hydrogen peroxidewas added dropwise at a temperature below 70° C. The solution was keptat the temperature for 4 hours and then cooled in an ice bath whereuponwhite crystals precipitated. The crystals were filtered out, collecting42.8 g (yield 80%) of the end compound,bis(4-n-hexyloxy-2-methylphenylsulfonyl)methane.

Synthesis Example 12

Synthesis of bis(4-n-hexyloxy-2-methylphenylsulfonyl)diazomethane

In 200 g of dichloromethane were dissolved 20 g (0.038 mol) of thebis(4-n-hexyloxy-2-methylphenylsulfonyl)methane in Synthesis Example 11and 11.3 g (0.057 mol) of p-toluenesulfonylazide. The solution wascooled in an ice bath, 5.8 g (0.038 mol) of diazabicycloundecene (DBU)was added at a temperature below 5° C. The solution was ripened at thetemperature for 15 minutes, after which 100 g of water and 10 g of conc.hydrochloric acid (12N) were added. The organic layer was separated andwashed with 100 g of water, after which the solvent was removed by arotary evaporator, obtaining 32 g of an oily matter. It was purified bysilica gel column chromatography (eluent: dichloromethane), obtaining11.1 g (yield 52%) of the end compound,bis(4-n-hexyloxy-2-methylphenylsulfonyl)diazomethane.

The thus obtained bis(4-n-hexyloxy-2-methylphenylsulfonyl)diazomethanewas analyzed by NMR spectroscopy and IR spectroscopy, with the resultsshown below.

¹H-NMR: CDCl₃ (ppm) (1) Ha 0.894-0.940 triplet 6H (2) Hb 1.33-1.50multiplet 12H (3) Hc 1.745-1.839 quintuplet 4H (4) Hd 3.967-4.010triplet 4H (5) He, Hg 6.722-6.747 multiplet 4H (6) Hf 7.776-7.808doublet 2H (7) Hh 2.533 singlet 6H IR: cm⁻¹ 2956, 2933, 2860, 2104,1604, 1566, 1473, 1346, 1298, 1254, 1227, 1169, 1142, 1065, 993, 970,864, 804, 715, 700, 675, 631, 596, 577, 532

Synthesis Example 13

Synthesis of 4-n-decyloxythiophenol

In 200 g of ethanol were dissolved 86.5 g (0.5 mol) of 4-bromophenol and22 g (0.55 mol) of sodium hydroxide. To the solution at 70° C., 121.8 g(0.55 mol) of n-decyl bromide was added dropwise. The solution wasallowed to ripen for 4 hours and cooled to room temperature, after which120 g of water was added. The oily matter was separated therefrom andconcentrated by a rotary evaporator, followed by vacuum distillation(boiling point 143-145° C./0.5 Torr), yielding 90 g of4-n-decyloxyphenyl bromide.

Using 10.9 g (0.447 mol) of metallic magnesium, 335 g oftetrahydrofuran, and 140 g (0.447 mol) of the above 4-n-decyloxyphenylbromide, a Grignard reagent was prepared in a conventional manner. TheGrignard reagent was ice cooled, to which 14.3 g (0.447 mol) ofcolloidal sulfur was added at a temperature below 20° C. The solutionwas ripened for 2 hours at room temperature, then ice cooled again. Tothe solution, 30 g of conc. hydrochloric acid (12N) and 150 g of waterwere added. The organic layer thus separated was concentrated, obtaining77 g of an oily matter. Vacuum distillation (boiling point 145-149°C./0.4 Torr) of the oily matter yielded 54 g (yield 40%) of the endcompound, 4-n-decyloxythiophenol.

Synthesis Example 14

Synthesis of formaldehyde bis(4-n-decyloxyphenylthio)acetal

In 200 g of ethanol were dissolved 54 g (0.203 mol) of the above4-n-decyloxythiophenol and 8.5 g (0.21 mol) of sodium hydroxide. To thesolution, 12.9 g (0.15 mol) of dichloromethane was added dropwise at atemperature below 50° C. The solution was heated at 60° C. in an oilbath and ripened for 3 hours at the temperature. It was allowed to coolto room temperature, after which 100 g of water and 150 g ofdichloromethane were added. The organic layer was separated and thesolvent was removed therefrom by a rotary evaporator, collecting 55 g(yield 100%) of the end compound, formaldehydebis(4-n-decyloxyphenylthio)acetal.

Synthesis Example 15

Synthesis of bis(4-n-decyloxyphenylsulfonyl)methane

To 220 g of ethanol were added 55 g (0.101 mol) of the formaldehydebis(4-n-decyloxyphenylthio)acetal in Synthesis Example 14 and 1.0 g(0.003 mol) of sodium tungstate. The solution was heated at 65° C. in anoil bath, to which 53 g (0.55 mol) of aqueous hydrogen peroxide wasadded dropwise at a temperature below 70° C. The solution was kept atthe temperature for 4 hours and then cooled in an ice bath whereuponwhite crystals precipitated. The crystals were filtered out, collecting52 g (yield 85%) of the end compound,bis(4-n-decyloxyphenylsulfonyl)methane.

Synthesis Example 16

Synthesis of bis(4-n-decyloxyphenylsulfonyl)diazomethane

In 100 g of dichloromethane were dissolved 10 g (0.016 mol) of thebis(4-n-decyloxyphenylsulfonyl)methane in Synthesis Example 15 and 3.9 g(0.02 mol) of p-toluene-sulfonylazide. The solution was cooled in an icebath, 2.4 g (0.016 mol) of diazabicycloundecene (DBU) was added at atemperature below 5° C. The solution was ripened at the temperature for15 minutes, after which 50 g of water and 5 g of conc. hydrochloric acid(12N) were added. The organic layer was separated and washed with 100 gof water, after which the solvent was removed by a rotary evaporator,obtaining 14 g of an oily matter. This was purified by silica gel columnchromatography (eluent: dichloromethane), obtaining 7.0 g (yield 69%) ofthe end compound, bis(4-n-decyloxyphenylsulfonyl)diazomethane.

The thus obtained bis(4-n-decyloxyphenylsulfonyl)diazomethane wasanalyzed by NMR spectroscopy and IR spectroscopy, with the results shownbelow.

¹H-NMR: CDCl₃ (ppm) (1) Ha 0.861-0.906 triplet 6H (2) Hb 1.20-1.50multiplet 28H (3) Hc 1.767-1.859 quintuplet 4H (4) Hd 4.011-4.055triplet 4H (5) He 6.970-7.000 doublet 4H (6) Hf 7.881-7.911 doublet 4HIR: cm⁻¹ 2920, 2852, 2106, 1593, 1497, 1475, 1350, 1311, 1263, 1213,1178, 1153, 1115, 1084, 1014, 982, 833, 719, 687, 629, 580

Synthesis Example 17

Synthesis of 4-n-decyloxythiophenol

In 200 g of ethanol were dissolved 86.5 g (0.5 mol) of 4-bromophenol and22 g (0.55 mol) of sodium hydroxide. To the solution at 70° C., 137 g(0.55 mol) of n-dodecyl bromide was added dropwise. The solution wasallowed to ripen for 4 hours and cooled to room temperature, after which120 g of water was added. The oily matter separated therefrom wasconcentrated by a rotary evaporator, followed by vacuum distillation(boiling point 178-180° C./0.5 Torr), yielding 110 g of4-n-dodecyloxyphenyl bromide.

Using 7.8 g (0.322 mol) of metallic magnesium, 240 g of tetrahydrofuran,and 110 g (0.322 mol) of the above 4-n-dodecyloxyphenyl bromide, aGrignard reagent was prepared in a conventional manner. The Grignardreagent was ice cooled, to which 7.82 g (0.322 mol) of colloidal sulfurwas added at a temperature below 20° C. The solution was ripened for 2hours at room temperature, then ice cooled again. To the solution, 20 gof conc. hydrochloric acid (12N) and 100 g of water were added. Theorganic layer thus separated was concentrated, obtaining 100 g of anoily matter. Vacuum distillation (boiling point 185-190° C./0.4 Torr) ofthe oily matter yielded 33 g (yield 35%) of the end compound,4-n-dodecyloxythiophenol.

Synthesis Example 18

Synthesis of formaldehyde bis(4-n-dodecyloxyphenylthio)acetal

In 165 g of ethanol were dissolved 33 g (0.112 mol) of the above4-n-dodecyloxythiophenol and 4.8 g (0.12 mol) of sodium hydroxide. Tothe solution, 7.6 g (0.089 mol) of dichloromethane was added dropwise ata temperature below 50° C. The solution was heated at 60° C. in an oilbath and ripened for 3 hours at the temperature. It was allowed to coolto room temperature, after which 100 g of water and 100 g ofdichloromethane were added. The organic layer was separated and thesolvent was removed therefrom by a rotary evaporator, collecting 30 g(yield 89%) of the end compound, formaldehydebis(4-n-dodecyloxyphenylthio)acetal.

Synthesis Example 19

Synthesis of bis(4-n-dodecyloxyphenylsulfonyl)methane

To 150 g of ethanol were added 30 g (0.05 mol) of the formaldehydebis(4-n-dodecyloxyphenylthio)acetal in Synthesis Example 18 and 0.3 g(0.001 mol) of sodium tungstate. The solution was heated at 65° C. in anoil bath, to which 24 g (0.25 mol) of aqueous hydrogen peroxide wasadded dropwise at a temperature below 70° C. The solution was kept atthe temperature for 4 hours and then cooled in an ice bath whereuponwhite crystals precipitated. The crystals were filtered out, collecting31 g (yield 93%) of the end compound,bis(4-n-dodecyloxyphenylsulfonyl)methane.

Synthesis Example 20

Synthesis of bis(4-n-dodecyloxyphenylsulfonyl)diazomethane

In 100 g of dichloromethane were dissolved 15 g (0.022 mol) of thebis(4-n-dodecyloxyphenylsulfonyl)methane in Synthesis Example 19 and 5.9g (0.03 mol) of p-toluene-sulfonylazide. The solution was cooled in anice bath, 3.4 g (0.022 mol) of diazabicycloundecene (DBU) was added at atemperature below 5° C. The solution was ripened at the temperature for15 minutes, after which 100 g of water and 8 g of conc. hydrochloricacid (12N) were added. The organic layer was separated and washed with100 g of water, after which the solvent was removed by a rotaryevaporator, obtaining 20 g of an oily matter. It was purified by silicagel column chromatography (eluent: dichloromethane), obtaining 11 g(yield 70%) of the end compound,bis(4-n-dodecyloxyphenylsulfonyl)diazomethane.

The thus obtained bis(4-n-dodecyloxyphenylsulfonyl)diazomethane wasanalyzed by NMR spectroscopy and IR spectroscopy, with the results shownbelow.

¹H-NMR: CDCl₃ (ppm) (1) Ha 0.868-0.903 triplet 6H (2) Hb 1.20-1.50multiplet 36H (3) Hc 1.767-1.859 quintuplet 4H (4) Hd 4.012-4.055triplet 4H (5) He 6.970-7.000 doublet 4H (6) Hf 7.881-7.911 doublet 4HIR: cm⁻¹ 2920, 2850, 2116, 1593, 1497, 1471, 1348, 1329, 1306, 1267,1221, 1159, 1080, 997, 976, 835, 721, 690, 633, 580, 563

Synthesis Example 21

Synthesis of bis(4-n-octyloxyphenylsulfonyl)diazomethane

The end product, bis(4-n-octyloxyphenylsulfonyl)diazomethane, wassynthesized as in Synthesis Examples 5 to 8 except that n-octyl bromidewas used instead of the n-hexyl bromide in Synthesis Example 5.

The thus obtained bis(4-n-octyloxyphenylsulfonyl)diazomethane wasanalyzed by NMR spectroscopy and IR spectroscopy, with the results shownbelow.

¹H-NMR: CDCl₃ (ppm) (1) Ha 0.869-0.914 triplet 6H (2) Hb 1.30-1.49multiplet 20H (3) Hc 1.767-1.860 quintuplet 4H (4) Hd 4.012-4.055triplet 4H (5) He 6.970-7.000 doublet 4H (6) Hf 7.881-7.910 doublet 4HIR: cm⁻¹ 2922, 2856, 2104, 1593, 1574, 1498, 1473, 1398, 1356, 1340,1308, 1267, 1227, 1149, 1080, 1030, 999, 976, 839, 719, 690, 625, 579,565

Synthesis Example 22

Synthesis of bis(4-n-octylphenylsulfonyl)diazomethane

The end product, bis(4-n-octylphenylsulfonyl)diazomethane, wassynthesized as in Synthesis Examples 5 to 8 except that commerciallyavailable 1-bromo-4-octylbenzene (Tokyo Chemical Industry Co., Ltd.) wasused instead of the 4-n-hexyloxyphenyl bromide obtained as theintermediate in Synthesis Example 5.

The thus obtained bis(4-n-octylphenylsulfonyl)diazomethane was analyzedby NMR spectroscopy and IR spectroscopy, with the results shown below.

¹H-NMR: CDCl₃ (ppm) (1) Ha 0.863-0.908 triplet 6H (2) Hb 1.20-1.40multiplet 20H (3) Hc 1.596-1.694 quintuplet 4H (4) Hd 2.673-2.734triplet 4H (5) He 7.344-7.373 doublet 4H (6) Hf 7.874-7.903 doublet 4HIR: cm⁻¹ 2924, 2856, 2104, 1595, 1470, 1406, 1358, 1344, 1319, 1217,1157, 1120, 1082, 978, 843, 698, 677, 623, 582, 569, 530

Synthesis Example 23

Synthesis of bis(3,5-dimethyl-4-n-hexyloxyphenylsulfonyl)diazomethane

The end product,bis(3,5-dimethyl-4-n-hexyloxyphenylsulfonyl)diazomethane, wassynthesized as in Synthesis Examples 5 to 8 except that2,6-dimethyl-4-bromophenol was used instead of the bromophenol inSynthesis Example 5.

The thus obtainedbis(3,5-dimethyl-4-n-hexyloxyphenylsulfonyl)diazomethane was analyzed byNMR spectroscopy and IR spectroscopy, with the results shown below.

¹H-NMR: CDCl₃ (ppm) (1) Ha 0.898-0.945 triplet 6H (2) Hb 1.30-1.56multiplet 12H (3) Hc 1.770-1.864 multiplet 4H (4) Hd 3.788-3.831 triplet4H (5) He 2.321 singlet 12H (6) Hf 7.594 singlet 4H IR: cm⁻¹ 2954, 2929,2856, 2117, 1470, 1379, 1342, 1281, 1215, 1151, 1101, 980, 930, 897,708, 669, 613, 534

Synthesis Example 24

Synthesis of 4-bromo-2,5-dimethyl-n-hexyloxybenzene

In 250 g of ethanol were dissolved 250 g (2.05 mol) of2,5-dimethylphenol (or p-xylenol), 90 g (2.25 mol) of sodium hydroxideand 371 g (2.25 mol) of n-hexyl bromide. The solution was heated for 2hours in an oil bath at 80° C. Water, 500 g, was added to the reactionmixture, from which an oily matter was separated. Vacuum distillation ofthe oily matter yielded 384 g of 2,5-dimethyl-1-n-hexyloxy-benzene.Next, 129 g (0.625 mol) of 2,5-dimethyl-1-n-hexyloxybenzene wasdissolved in 625 g of 1,2-dichloroethane. To the solution kept in an icebath, 100 g (0.625 mol) of bromine was added dropwise at a temperaturebelow 5C. At the end of dropwise addition, 500 g of water was added. Theorganic layer was separated therefrom and washed with 300 g of anaqueous solution of 5 wt % sodium hydrogen carbonate. The organic layerwas concentrated to remove the solvent, leaving an oily matter. Vacuumdistillation (boiling point 114-124° C./0.5 Torr) of the oily matteryielded 174 g of 4-bromo-2,5-dimethyl-n-hexyloxybenzene.

At the end of distillation, the product,4-bromo-2,5-dimethyl-n-hexyloxybenzene crystallized.

Synthesis Example 25

Synthesis of 2,5-dimethyl-4-n-hexyloxythiophenol

Using 14.8 g (0.61 mol) of metallic magnesium, 426 g of tetrahydrofuran,and 174 g (0.61 mol) of the 4-bromo-2,5-dimethyl-n-hexyloxybenzeneobtained in Synthesis Example 24, a Grignard reagent was prepared in aconventional manner. In an ice bath, 18.5 g (0.578 mol) of colloidalsulfur was added to the Grignard reagent at a temperature below 20° C.The solution was ripened for 2 hours at room temperature, then icecooled again. To the solution, 90 g of conc. hydrochloric acid (12N) and300 g of water were added. The organic layer was separated andconcentrated, obtaining 145 g of an oily matter. Vacuum distillation(boiling point 131-134° C./0.5 Torr) of the oily matter yielded 75 g ofthe end compound, 2,5-dimethyl-4-n-hexyloxythiophenol.

Synthesis Example 26

Synthesis of bis(2,5-dimethyl-4-n-hexyloxyphenylsulfonyl)diazomethane

The end product,bis(2,5-dimethyl-4-n-hexyloxyphenylsulfonyl)diazomethane was synthesizedas in Synthesis Examples 5 to 8 except that2,5-dimethyl-4-n-hexyloxythiophenol in Synthesis Example 25 was usedinstead of the 4-n-hexyloxythiophenol in Synthesis Example 6.

The thus obtainedbis(2,5-dimethyl-4-n-hexyloxyphenylsulfonyl)diazomethane was analyzed byNMR spectroscopy and IR spectroscopy, with the results shown below.

¹H-NMR: CDCl₃ (ppm) (1) Ha 0.896-0.943 triplet 6H (2) Hb 1.30-1.42multiplet 8H (3) Hc 1.43-1.53 multiplet 4H (4) Hd 1.76-1.86 multiplet 4H(5) He 3.93-3.97 triplet 4H (6) Hf 2.12 singlet 6H (7) Hg 2.48 singlet6H (8) Hi 6.51 singlet 2H (9) Hj 7.49 singlet 2H IR: cm⁻¹ 2956, 2935,2858, 2102, 1602, 1562, 1502, 1465, 1392, 1375, 1340, 1327, 1263, 1232,1143, 1136, 1045, 1036, 964, 677, 613, 580, 562, 540

Synthesis Example 27

Synthesis of bis(4-n-hexyloxy-2,3,5-trimethylphenylsulfonyl)diazomethane

The end product,bis(4-n-hexyloxy-2,3,5-trimethyl-phenylsulfonyl)diazomethane wassynthesized as in Synthesis Examples 24 to 26 except that2,3,6-trimethylphenol was used instead of the 2,5-dimethylphenol inSynthesis Example 24.

The thus obtainedbis(4-n-hexyloxy-2,3,5-trimethyl-phenylsulfonyl)diazomethane wasanalyzed by NMR spectroscopy and IR spectroscopy, with the results shownbelow.

¹H-NMR: CDCl₃ (ppm) (1) Ha 0.90-0.95 triplet 6H (2) Hb 1.33-1.40multiplet 8H (3) Hc 1.45-1.54 multiplet 4H (4) Hd 1.75-1.84 multiplet 4H(5) He 3.67-3.71 triplet 4H (6) Hf 2.11 singlet 6H (7) Hg 2.21 singlet6H (8) Hi 2.34 singlet 6H (9) Hj 7.50 singlet 2H IR: cm⁻¹ 2957, 2927,2860, 2098, 1465, 1377, 1344, 1329, 1277, 1228, 1211, 1149, 1139, 1093,669, 636, 607, 580, 569, 548

Synthesis Example 28

Synthesis ofbis(2-methyl-4-n-hexyloxy-5-isopropylphenylsulfonyl)diazomethane

The end product,bis(2-methyl-4-n-hexyloxy-5-isopropylphenylsulfonyl)diazomethane wassynthesized as in Synthesis Examples 24 to 26 except thatthymol(2-isopropyl-5-methylphenol) was used instead of the2,5-dimethylphenol in Synthesis Example 24.

The thus obtainedbis(2-methyl-4-n-hexyloxy-5-isopropylphenylsulfonyl)diazomethane wasanalyzed by NMR spectroscopy and IR spectroscopy, with the results shownbelow.

¹H-NMR: CDCl₃ (ppm) (1) Ha 0.90-0.94 triplet 6H (2) Hb 1.32-1.40multiplet 8H (3) Hc 1.44-1.54 multiplet 4H (4) Hd 1.78-1.87 multiplet 4H(5) He 3.99-4.03 triplet 4H (6) Hf 1.215-1.238 doublet 12H (7) Hg3.19-3.33 multiplet 2H (8) Hi 6.67 singlet 2H (9) Hj 2.56 singlet 6H(10) Hh 7.75 singlet 2H IR: cm⁻¹ 2958, 2933, 2866, 2110, 1601, 1558,1500, 1469, 1456, 1390, 1363, 1350, 1336, 1325, 1282, 1255, 1144, 1122,1076, 1041, 1030, 1012, 968, 902, 733, 677, 652, 596, 579, 548, 517

Examples 1-24 and Comparative Examples 1-3

Resist materials were formulated in accordance with the formulationshown in Tables 1-to 3. The components used are shown below.

Polymer A: poly(p-hydroxystyrene) in which hydroxyl groups are protectedwith 15 mol % of 1-ethoxyethyl groups and 15 mol % oftert-butoxycarbonyl groups, having a weight average molecular weight of12,000.

Polymer B: poly(p-hydroxystyrene) in which hydroxyl groups are protectedwith 30 mol % of 1-ethoxyethyl groups, having a weight average molecularweight of 12,000.

Polymer C: poly(p-hydroxystyrene) in which hydroxyl groups are protectedwith 15 mol % of 1-ethoxyethyl groups and 10 mol % oftert-butoxycarbonyl groups, having a weight average molecular weight of11,000.

Polymer D: poly(p-hydroxystyrene) in which hydroxyl groups are protectedwith 25 mol % of 1-ethoxyethyl groups and crosslinked with 3 mol % of1,2-propanediol divinyl ether, having a weight average molecular weightof 13,000.

Polymer E: poly(p-hydroxystyrene) in which hydroxyl groups are protectedwith 25 mol % of tert-butoxycarbonyl groups, having a weight averagemolecular weight of 12,000.

Polymer F: p-hydroxystyrene/2-ethyl-2-adamantyl acrylate copolymerhaving a compositional ratio (molar ratio) of 70:30 and a weight averagemolecular weight of 15,000.

Polymer G: p-hydroxystyrene/1-ethyl-1-norbornene methacrylate copolymerhaving a compositional ratio (molar ratio) of 70:30 and a weight averagemolecular weight of 15,000.

Polymer H: p-hydroxystyrene/tert-butyl acrylate copolymer having acompositional ratio (molar ratio) of 65:35 and a weight averagemolecular weight of 15,000.

Polymer I: p-hydroxystyrene/1-ethylcyclopentyl methacrylate copolymerhaving a compositional ratio (molar ratio) of 65:35 and a weight averagemolecular weight of 15,000.

Polymer J: p-hydroxystyrene/1-ethylcyclopentyl methacrylate/styrenecopolymer having a compositional ratio (molar ratio) of 65:10:25 and aweight average molecular weight of 12,000.

Polymer K: p-hydroxystyrene/indene copolymer having a compositionalratio (molar ratio) of 80:20 in which hydroxyl groups on hydroxystyreneare protected with 20 mol % of tert-butoxycarbonyl groups, having aweight average molecular weight of 10,000.

Polymer L: p-hydroxystyrene/indene/1-ethyl-1-norbornene methacrylatecopolymer having a compositional ratio (molar ratio) of 70:10:20 and aweight average molecular weight of 10,000.

Polymer M: p-hydroxystyrene/indene/1-ethyl-1-norbornene methacrylatecopolymer having a compositional ratio (molar ratio) of 70:15:15 and aweight average molecular weight of 10,000.

Polymer N: poly(p-hydroxystyrene) in which hydroxyl groups are protectedwith 8 mol % of acetyl groups, having a weight average molecular weightof 8,000.

PAG1: bis(4-n-hexyloxy-2-methylphenylsulfonyl)diazomethane

PAG2: bis(4-n-octylphenylsulfonyl)diazomethane

PAG3: bis(3,5-dimethyl-4-n-hexyloxyphenylsulfonyl)diazomethane

PAG4: bis(2,5-dimethyl-4-n-hexyloxyphenylsulfonyl)diazomethane

PAG5: (4-tert-butoxyphenyl)diphenylsulfonium 10-camphorsulfonate

PAG6: bis(4-methoxyphenylsulfonyl)diazomethane

PAG7: bis(cyclohexylsulfonyl)diazomethane

PAG8: bis(2,4-dimethylphenylsulfonyl)diazomethane

PAG9: N-10-camphorsulfonyloxysuccinimide

Crosslinker A: 1,3,5,7-tetramethoxymethylglycoluril

Dissolution inhibitor: bis(4-(2′-tetrahydropyranyloxy)phenyl)methane

Basic compound A: tri-n-butylamine

Basic compound B: tris(2-methoxyethyl)amine

Organic acid derivative A: 4,4-bis(4′-hydroxyphenyl)valeric acid

Organic acid derivative B: salicylic acid

Surfactant A: FC-430 (Sumitomo 3M K.K.)

Surfactant B: Surflon S-381 (Asahi Glass K.K.)

UV absorber: 9,10-dimethylanthracene

Solvent A: propylene glycol methyl ether acetate

Solvent B: ethyl lactate

The resist materials thus obtained were each filtered through a 0.2-μmTeflon filter, thereby giving resist solutions. These resist solutionswere spin-coated onto silicon wafers having an organic antireflectionfilm (Brewer Science, DUV-44) of 800 Å thick coated thereon, so as togive a dry thickness of 0.6 μm.

The coated wafer was then baked on a hot plate at 100° C. for 90seconds. The resist films were exposed to ⅔ annular illumination usingan excimer laser stepper NSR-S202A (Nikon K.K., NA 0.6), then baked(PEB) at 110° C. for 90 seconds, and developed with a solution of 2.38%tetramethylammonium hydroxide in water, thereby giving positive patterns(Examples 1 to 23 and Comparative Examples 1-3) or negative pattern(Example 24).

The resulting resist patterns were evaluated as described below.

Resist Pattern Evaluation

The optimum exposure dose (sensitivity Eop) was the exposure dose whichprovided a 1:1 resolution at the top and bottom of a 0.18-μmline-and-space pattern. The minimum line width (μm) of a line-and-spacepattern which was ascertained separate at this dose was the resolutionof a test resist. The shape in cross section of the resolved resistpattern was examined under a scanning electron microscope. The depth offocus (DOF) was determined by offsetting the focal point and judging theresist to be satisfactory when the resist pattern shape was keptrectangular and the resist pattern film thickness was kept above 80% ofthat at accurate focusing.

The PED stability of a resist was evaluated by effecting post-exposurebake (PED) after 24 hours of holding from exposure at the optimum doseand determining a variation in line width (or groove width for thenegative resist). The less the variation, the greater is the PEDstability.

The results of resist pattern evaluation are shown in Table 4.

Other Evaluation

The solubility of resist material in a solvent mixture was examined byvisual observation and in terms of clogging upon filtration.

With respect to the applicability of a resist solution, uneven coatingwas visually observed. Additionally, using a film gage Clean Track Mark8 (Dai-Nippon Screen Manufacturing Co., Ltd., Light InterferenceThickness Measuring Apparatus Ramda Ace VM-3010), the thickness of aresist film on a common wafer was measured at different positions, basedon which a variation from the desired coating thickness (0.6 μm) wascalculated. The applicability was rated “good” when the variation waswithin 0.5% (that is, within 0.003 μm), “unacceptable” when thevariation was within 1%, and “poor” when the variation was more than 1%.

Storage stability was judged in terms of foreign matter precipitation orsensitivity change with the passage of time. After the resist solutionwas aged for 100 days at the longest, the number of particles of greaterthan 0.3 μm per ml of the resist solution was counted by means of aparticle counter KL-20A (Rion K.K.), and the foreign matterprecipitation was determined “good” when the number of particles is notmore than 5. Also, the sensitivity change was rated “good” when a changewith time of sensitivity (Eop) was within 5% from that immediately afterpreparation, and “poor” when the change is more than 5%.

Debris appearing on the developed pattern was observed under a scanningelectron microscope (TDSEM) model S-7280H (Hitachi, Ltd.). The resistfilm was rated “good” when the number of foreign particles was up to 10per 100 μm², “unacceptable” when from 11 to 15, and “poor” when morethan 15.

Debris left after resist peeling was examined using a surface scannerSurf-Scan 6220 (Tencol Instruments). A resist-coated 8-inch wafer wassubjected to entire exposure rather than patterned exposure, processedin a conventional manner, and developed with a 2.38% TMAH solutionbefore the resist film was peeled off (only the resist film in theexposed area was peeled). After the resist film was peeled, the waferwas examined and rated “good” when the number of foreign particles ofgreater than 0.20 μm was up to 100, “unacceptable” when from 101 to 150,and “poor” when more than 150.

The results are shown in Table 5.

TABLE 1 Composition Example (pbw) 1 2 3 4 5 6 7 8 9 10 11 12 Polymer A80 40 Polymer B 80 Polymer C 80 Polymer D 80 Polymer E 80 Polymer F 80Polymer G 80 Polymer H 80 Polymer I 80 Polymer J 80 Polymer K 80 PolymerL 80 Polymer M Polymer N PAG1 2 2 1 PAG2 2 1 2 2 PAG3 2 2 2 PAG4 2 2 2PAG5 1 1 2 PAG6 1 PAG7 1 PAG8 1 PAG9 1 1 Dissolution inhibitor Basiccompound A 0.3 0.3 0.2 0.3 0.3 0.3 0.3 0.3 Basic compound B 0.2 0.3 0.30.3 0.3 Organic acid 0.5 0.5 0.5 derivative A Organic acid 0.5derivative B Surfactant A 0.3 0.3 0.3 0.3 0.3 0.3 Surfactant B 0.3 0.30.3 0.3 0.3 0.3 UV absorber Solvent A 385 385 385 385 280 382 385 385385 385 280 385 Solvent B 105 105

TABLE 2 Composition Example (pbw) 13 14 15 16 17 18 19 20 21 22 23 24Polymer A 40 60 Polymer B 60 75 Polymer C 40 40 Polymer D 70 40 60 40Polymer E 40 10 Polymer F Polymer G 40 Polymer H Polymer I 10 20 PolymerJ Polymer K 40 Polymer L 40 20 70 Polymer M 40 20 Polymer N 80 PAG1 2 22 PAG2 2 2 2 PAG3 2 2 1 2 2 PAG4 2 2 2 2 PAG5 2 1 1 1 PAG6 2 2 PAG7 11.5 1.5 1 PAG8 0.5 PAG9 1 1 1 Crosslinker A 20 Dissolution 5 inhibitorBasic compound A 0.2 0.3 0.3 0.3 Basic compound B 0.3 0.3 0.3 0.3 0.20.3 0.3 0.3 0.3 Organic acid 0.5 0.5 derivative A Organic acid 0.3derivative B Surfactant A 0.3 0.3 0.3 0.3 0.3 0.3 Surfactant B 0.3 0.30.3 0.3 0.3 UV absorber 0.5 Solvent A 385 385 280 280 385 385 385 280385 385 280 385 Solvent B 105 105 105 105

TABLE 3 Composition Comparative Example (pbw) 1 2 3 Polymer A 80 40Polymer E 80 Polymer K 40 PAG5 PAG6 2.5 PAG7 1 PAG8 2.5 2.5 PAG9 1Dissolution inhibitor Basic compound A 0.125 Basic compound B 0.1250.125 Organic acid derivative A 0.5 Organic acid derivative B SurfactantA 0.25 0.25 Surfactant B 0 0.25 UV absorber Solvent A 385 385 385Solvent B

TABLE 4 24 hr PED DOF at dimensional Sensitivity Resolution 0.18 μmOff-focus stability (mJ/cm²) (μm) Profile (μm) profile** (nm) Example 131 0.14 rectangular 1.1 rectangular −8 Example 2 27 0.14 rectangular 1.1rectangular −10 Example 3 29 0.14 rectangular 1.0 rectangular −9 Example4 28 0.14 rectangular 1.1 rectangular −10 Example 5 35 0.16 rectangular1.0 rectangular 10 Example 6 33 0.15 rectangular 1.1 rectangular −8Example 7 32 0.14 rectangular 1.1 rectangular −10 Example 8 35 0.16rectangular 1.0 rectangular −8 Example 9 32 0.14 rectangular 1.1rectangular −10 Example 10 34 0.15 rectangular 1.0 rectangular −8Example 11 37 0.16 rectangular 0.8 rectangular 8 Example 12 33 0.15rectangular 1.0 rectangular −10 Example 13 32 0.15 rectangular 1.0rectangular −8 Example 14 28 0.14 rectangular 1.0 rectangular −10Example 15 30 0.14 rectangular 1.1 rectangular −8 Example 16 29 0.15rectangular 1.0 rectangular −8 Example 17 32 0.14 rectangular 1.0rectangular −10 Example 18 30 0.14 rectangular 1.0 rectangular −8Example 19 35 0.15 rectangular 1.0 rectangular −8 Example 20 28 0.14rectangular 1.1 rectangular −10 Example 21 32 0.15 rectangular 1.0rectangular −10 Example 22 35 0.14 rectangular 1.1 rectangular −10Example 23 28 0.14 rectangular 1.1 rectangular −8 Example 24 40 0.16rectangular 0.8 rectangular −8 Comparative 25 0.15 forward taper 0.8forward taper −10 Example 1 Comparative 32 0.15 rounded head 0.8 roundedhead −8 Example 2 Comparative 35 0.15 forward taper 0.8 forward taper−10 Example 3 **the shape of a pattern obtained when the focus wasshifted −0.4 μm to minus side upon DOF measurement at 0.18 μm

TABLE 5 Debris Foreign 100 day after particles Dis- Applica- storagedevelop- after solution tion stability ment peeling Example 1 good goodgood good good Example 2 good good good good good Example 3 good goodgood good good Example 4 good good good good good Example 5 good goodgood good good Example 6 good good good good good Example 7 good goodgood good good Example 8 good good good good good Example 9 good goodgood good good Example 10 good good good good good Example 11 good goodgood good good Example 12 good good good good good Example 13 good goodgood good good Example 14 good good good good good Example 15 good goodgood good good Example 16 good good good good good Example 17 good goodgood good good Example 18 good good good good good Example 19 good goodgood good good Example 20 good good good good good Example 21 good goodgood good good Example 22 good good good good good Example 23 good goodgood good good Example 24 good good good good good Com- good good <30days poor unaccept- parative (sensi- able Example 1 tivity changed) Com-good good good unaccept- poor parative able Example 2 Com- good goodgood poor poor parative Example 3

Examples 25-30 and Comparative Examples 4-8

Resist solutions having formulations shown in Table 6 were prepared. Thecomponents in Table 6 other than the components described above were asfollows.

PAG10: bis(4-ethyloxyphenylsulfonyl)diazomethane

PAG11: bis(4-n-propyloxyphenylsulfonyl)diazomethane

PAG12: bis(4-tert-butylphenylsulfonyl)diazomethane

PAG13: bis(4-cyclohexyloxyphenylsulfonyl)diazomethane

PAG14: bis(4-n-butyloxyphenylsulfonyl)diazomethane

PAG15: bis(4-n-hexyloxyphenylsulfonyl)diazomethane

PAG16: bis(4-n-octyloxyphenylsulfonyl)diazomethane

PAG17: bis(4-n-decyloxyphenylsulfonyl)diazomethane

PAG18: bis(4-n-dodecyloxyphenylsulfonyl)diazomethane

TABLE 6 Comparative Example Example 4 5 6 7 8 25 26 27 28 29 30 PolymerA 80 80 80 80 80 80 80 80 80 80 80 PAG6 3.00 PAG10 3.22 PAG11 3.44 PAG123.41 PAG13 4.07 PAG14 3.66 PAG15 4.10 PAG16 4.54 PAG2 4.29 PAG17 4.98PAG18 5.42 Basic compound A 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3Surfactant A 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Solvent A 385385 385 385 385 385 385 385 385 385 385

The amounts of PAG10 to PAG18 and PAG 2 were adjusted so that the numberof moles of PAG10 to PAG18 and PAG 2 was the same as the number of molesof PAG6.

The resist solutions were filtered, then, the same steps including spincoating, baking, KrF excimer laser exposing and PEB were repeated in thesame manner as in Examples 1-24 and Comparative Examples 1-3. Afterdeveloping, the numbers of foreign particles visually observed in 100square μm were counted by using scanning electron microscope (TDSEMavailable from Hitachi, Ltd. model S9200) which enables more detailedobservation. The results are shown in Table 2.

TABLE 7 Comparative Example Example 4 5 6 7 8 25 26 27 28 29 30 Numberof 16-20 16-20 11-15 40-50 100≦ ≦3 ≦3 ≦3 ≦3 ≦3 ≦3 debris afterdevelopment

There have been described chemical amplification type resistcompositions comprising a specific sulfonyldiazomethane containing along-chain alkylphenyl or long-chain alkoxyphenyl group as the photoacidgenerator. The compositions have many advantages including improvedresolution, improved focus latitude, minimized line width variation orshape degradation even on long-term PED, minimized debris left aftercoating, development and peeling, and improved pattern profile afterdevelopment. Because of high resolution, the compositions are suited formicrofabrication, especially by deep UV lithography.

Japanese Patent Application No. 2001-300345 is incorporated herein byreference.

Although some preferred embodiments have been described, manymodifications and variations may be made thereto in light of the aboveteachings. It is therefore to be understood that the invention may bepracticed otherwise than as specifically described without departingfrom the scope of the appended claims.

What is claimed is:
 1. A sulfonyldiazomethane compound having thefollowing general formula (1):

wherein R is independently hydrogen or a substituted or unsubstituted,straight, branched or cyclic alkyl or alkoxy group of 1 to 4 carbonatoms, G is SO₂ or CO, R³ is a substituted or unsubstituted, straight,branched or cyclic alkyl group of 1 to 10 carbon atoms or a substitutedor unsubstituted aryl group of 6 to 14 carbon atoms, p is 1 or 2, q is 0or 1, satisfying p+q=2, n is 0 or 1, m is an integer of 3 to 11, and kis an integer of 0 to
 4. 2. A sulfonyldiazomethane compound having thefollowing general formula (1a):

wherein R is independently hydrogen or a substituted or unsubstituted,straight, branched or cyclic alkyl or alkoxy group of 1 to 4 carbonatoms, n is 0 or 1, m is an integer of 3 to 11, and k is an integer of 0to
 4. 3. A photoacid generator for a chemical amplification type resistcomposition comprising the sulfonyldiazomethane compound of claim 1 or2.
 4. A chemical amplification type resist composition comprising (A) aresin which changes its solubility in an alkaline developer under theaction of an acid, and (B) the sulfonyldiazomethane compound of claim 1which generates an acid upon exposure to radiation.
 5. A chemicalamplification type resist composition comprising (A) a resin whichchanges its solubility in an alkaline developer under the action of anacid, (B) the sulfonyldiazomethane compound of claim 1 which generatesan acid upon exposure to radiation, and (C) a compound capable ofgenerating an acid upon exposure to radiation, other than component (B).6. The resist composition of claim 4 or 5 wherein the resin (A) has suchsubstituent groups having C—O—C linkages that the solubility in analkaline developer changes as a result of scission of the C—O—C linkagesunder the action of an acid.
 7. The resist composition of claim 6wherein the resin (A) is a polymer containing phenolic hydroxyl groupsin which hydrogen atoms of the phenolic hydroxyl groups are substitutedwith acid labile groups of one or more types in a proportion of morethan 0 mol % to 80 mol % on the average of the entire hydrogen atoms ofthe phenolic hydroxyl groups, the polymer having a weight averagemolecular weight of 3,000 to 100,000.
 8. The resist composition of claim7 wherein the resin (A) is a polymer comprising recurring units of thefollowing general formula (2):

wherein R⁴ is hydrogen or methyl, R⁵ is a straight, branched or cyclicalkyl group of 1 to 8 carbon atoms, x is 0 or a positive integer, y is apositive integer, satisfying x+y≦5, R⁶ is an acid labile group, S and Tare positive integers, satisfying 0<T/(S+T)≦0.8, wherein the polymercontains units in which hydrogen atoms of phenolic hydroxyl groups arepartially substituted with acid labile groups of one or more types, aproportion of the acid labile group-bearing units is on the average frommore than 0 mol % to 80 mol % based on the entire polymer, and thepolymer has a weight average molecular weight of 3,000 to 100,000. 9.The resist composition of claim 6 wherein the resin (A) is a polymercomprising recurring units of the following general formula (2a′):

wherein R⁴ is hydrogen or methyl, R⁵ is a straight, branched or cyclicalkyl group of 1 to 8 carbon atoms, R⁶ is an acid labile group, R^(6a)is hydrogen or an acid labile group, at least some of R^(6a) being acidlabile groups, x is 0 or a positive integer, y is a positive integer,satisfying x+y≦5, M and N are positive integers, L is 0 or a positiveinteger, satisfying 0<N/(M+N+L)≦0.5 and 0<(N+L)/(M+N+L)≦0.8, wherein thepolymer contains on the average from more than 0 mol % to 50 mol % ofthose units based on acrylate and methacrylate, and also contains on theaverage from more than 0 mol % to 80 mol % of acid labile group-bearingunits, based on the entire polymer, and the polymer has a weight averagemolecular weight of 3,000 to 100,000.
 10. The resist composition ofclaim 6 wherein the resin (A) is a polymer comprising recurring units ofthe following general formula (2a″):

wherein R⁴ is hydrogen or methyl, R⁵ is a straight, branched or cyclicalkyl group of 1 to 8 carbon atoms, R⁶ is an acid labile group, R^(6a)is hydrogen or an acid labile group, at least some of R^(6a) being acidlabile groups, x is 0 or a positive integer, y is a positive integer,satisfying x+y≦5, yy is 0 or a positive integer, satisfying x+yy≦5, Aand B are positive integers, C, D and E each are 0 or a positiveinteger, satisfying 0<(B+E)/(A+B+C+D+E)≦0.5 and0<(C+D+E)/(A+B+C+D+E)≦0.8, wherein the polymer contains on the averagefrom more than 0 mol % to 50 mol % of those units based on indene and/orsubstituted indene, and also contains on the average from more than 0mol % to 80 mol % of acid labile group-bearing units, based on theentire polymer, and the polymer has a weight average molecular weight of3,000 to 100,000.
 11. The resist composition of claim 6, wherein theacid labile group is selected from the group consisting of groups of thefollowing general formulae (4) to (7), tertiary alkyl groups of 4 to 20carbon atoms, trialkylsilyl groups whose alkyl moieties each have 1 to 6carbon atoms, oxoalkyl groups of 4 to 20 carbon atoms, and

aryl-substituted alkyl groups of 7 to 20 carbon atoms, wherein R¹⁰ andR¹¹ each are hydrogen or a straight, branched or cyclic alkyl having 1to 18 carbon atoms, and R¹² is a monovalent hydrocarbon group of 1 to 18carbon atoms which may contain a heteroatom, a pair of R¹⁰ or R¹¹, andR¹⁰ and R¹²or R¹¹ and R¹² may together form a ring, with the provisothat R¹⁰R¹¹ and R¹² each are a straight or branched alkylene of 1 to 18carbon atoms when they form a ring, R¹³ is a tertiary alkyl group of 4to 20 carbon atoms, a trialkylsilyl group in which each of the alkylshas 1 to 6 carbon atoms, an oxoalkyl group of 4 to 20 carbon atoms or agroup of the formula (4), z is an integer of 0 to 6, R¹⁴ is a straight,branched or cyclic alkyl group of 1 to 8 carbon atoms or an aryl groupof 6 to 20 carbon atoms which may be substituted, h is 0 or 1, i is 0,1, 2 or 3, satisfying 2h+i=2 or 3, R¹⁵ is a straight, branched or cyclicalkyl group of 1 to 8 carbon atoms or an aryl group of 6 to 20 carbonatoms which may be substituted, or R¹⁶ to R²⁵ are each independentlyhydrogen or a monovalent hydrocarbon group of 1 to 15 carbon atoms whichmay contain a heteroatom, R¹⁶to R²⁵, taken together, may form a ringeach of R¹⁶ to R²⁵ is a divalent hydrocarbon group of 1 to 15 carbonatoms which may contain a heteroatom when they form a ring, or two ofR¹⁶ to R²⁵ which are attached to adjoining carbon atoms may bondtogether directly to form a double bond.
 12. The resist composition ofclaim 4 further comprising (D) a basic compound.
 13. The resistcomposition of claim 4 further comprising (E) an organic acidderivative.
 14. The resist composition of claim 4 further comprising anorganic solvent which contains a propylene glycol alkyl ether acetate,an alkyl lactate or a mixture thereof.
 15. A process for forming apattern, comprising the steps of: applying the resist composition ofclaim 4 onto a substrate to form a coating, heat treating the coatingand exposing the coating to high energy radiation with a wavelength ofup to 300 nm or electron beam through photomask, optionally heattreating the exposed coating, and developing the coating with adeveloper.